{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2025-12-14T01:33:56.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2025-12-14T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":46888,"title":"Diagonal Prod","description":null,"description_html":"\u003cdiv style = \"text-align: start; line-height: 20.44px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: none solid rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 20.8px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 10.4px; transform-origin: 407px 10.4px; vertical-align: baseline; \"\u003e\u003cdiv style=\"font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.4px; text-align: left; transform-origin: 384px 10.4px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003ereturn element by element product of two diagonal vectors of two matrixes\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = your_fcn_name(x)\r\n y = x;\r\nend","test_suite":"%%\r\nx = ones(3);\r\nz=zeros(3);\r\ny_correct = [0 0 0];\r\nassert(isequal(your_fcn_name(x,z),y_correct))\r\n\r\n%%\r\nx = ones(3);\r\nz=magic(3);\r\ny_correct = [8 5 2];\r\nassert(isequal(your_fcn_name(x,z),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":430136,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":90,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-10-17T15:43:56.000Z","updated_at":"2026-03-31T15:17:22.000Z","published_at":"2020-10-17T15:43:56.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ereturn element by element product of two diagonal vectors of two matrixes\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":1158,"title":"Sum the elements in either diagonal of a square matrix","description":"Sum the elements of a square matrix that lie on either the major diagonal or anti-diagonal. (Include all elements that are part of either of the diagonals).","description_html":"\u003cp\u003eSum the elements of a square matrix that lie on either the major diagonal or anti-diagonal. (Include all elements that are part of either of the diagonals).\u003c/p\u003e","function_template":"function y = sumDiagonalElements(x)\r\n y = 0;\r\nend","test_suite":"%%\r\nx = ones(2);\r\ny_correct = 4;\r\nassert(isequal(sumDiagonalElements(x),y_correct))\r\n%%\r\nx = ones(3);\r\ny_correct = 5;\r\nassert(isequal(sumDiagonalElements(x),y_correct))\r\n%%\r\nx = magic(8);\r\ny_correct = 520;\r\nassert(isequal(sumDiagonalElements(x),y_correct))\r\n%%\r\nx = magic(9);\r\ny_correct = 697;\r\nassert(isequal(sumDiagonalElements(x),y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":3,"created_by":8780,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":221,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2012-12-31T21:51:27.000Z","updated_at":"2026-02-09T20:24:17.000Z","published_at":"2012-12-31T21:53:05.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eSum the elements of a square matrix that lie on either the major diagonal or anti-diagonal. (Include all elements that are part of either of the diagonals).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2365,"title":"Generate this matrix","description":"For a given odd integer n, generate a matrix as follows:\r\n\r\nInput: n = 5;\r\nOutput:\r\n \r\n\r\n [ 2 1 0 0 0\r\n 1 1 1 0 0\r\n 0 1 0 1 0\r\n 0 0 1 1 1\r\n 0 0 0 1 2 ]\r\n\r\n\r\nInput: n=7;\r\nOutput:\r\n \r\n\r\n [ 3 1 0 0 0 0 0\r\n 1 2 1 0 0 0 0\r\n 0 1 1 1 0 0 0\r\n 0 0 1 0 1 0 0\r\n 0 0 0 1 1 1 0\r\n 0 0 0 0 1 2 1\r\n 0 0 0 0 0 1 3 ]\r\n\r\nFor further understanding of the pattern, please check the test suite.","description_html":"\u003cp\u003eFor a given odd integer n, generate a matrix as follows:\u003c/p\u003e\u003cp\u003eInput: n = 5;\r\nOutput:\u003c/p\u003e\u003cpre\u003e [ 2 1 0 0 0\r\n 1 1 1 0 0\r\n 0 1 0 1 0\r\n 0 0 1 1 1\r\n 0 0 0 1 2 ]\u003c/pre\u003e\u003cp\u003eInput: n=7;\r\nOutput:\u003c/p\u003e\u003cpre\u003e [ 3 1 0 0 0 0 0\r\n 1 2 1 0 0 0 0\r\n 0 1 1 1 0 0 0\r\n 0 0 1 0 1 0 0\r\n 0 0 0 1 1 1 0\r\n 0 0 0 0 1 2 1\r\n 0 0 0 0 0 1 3 ]\u003c/pre\u003e\u003cp\u003eFor further understanding of the pattern, please check the test suite.\u003c/p\u003e","function_template":"function y = your_fcn_name(x)\r\n\r\nend","test_suite":"%%\r\nx = 7;\r\ny_correct = [3 1 0 0 0 0 0;\r\n 1 2 1 0 0 0 0;\r\n 0 1 1 1 0 0 0;\r\n 0 0 1 0 1 0 0;\r\n 0 0 0 1 1 1 0;\r\n 0 0 0 0 1 2 1;\r\n 0 0 0 0 0 1 3];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n\r\n%%\r\nx = 5;\r\ny_correct =[2 1 0 0 0;\r\n 1 1 1 0 0;\r\n 0 1 0 1 0;\r\n 0 0 1 1 1;\r\n 0 0 0 1 2];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n\r\n%%\r\nx = 11;\r\ny_correct =[5 1 0 0 0 0 0 0 0 0 0;\r\n 1 4 1 0 0 0 0 0 0 0 0;\r\n 0 1 3 1 0 0 0 0 0 0 0;\r\n 0 0 1 2 1 0 0 0 0 0 0;\r\n 0 0 0 1 1 1 0 0 0 0 0;\r\n 0 0 0 0 1 0 1 0 0 0 0;\r\n 0 0 0 0 0 1 1 1 0 0 0;\r\n 0 0 0 0 0 0 1 2 1 0 0;\r\n 0 0 0 0 0 0 0 1 3 1 0;\r\n 0 0 0 0 0 0 0 0 1 4 1;\r\n 0 0 0 0 0 0 0 0 0 1 5];\r\nassert(isequal(your_fcn_name(x),y_correct));\r\n\r\n%%\r\nx = 5;\r\ny_correct =[2 1 0 0 0;\r\n 1 1 1 0 0;\r\n 0 1 0 1 0;\r\n 0 0 1 1 1;\r\n 0 0 0 1 2];\r\nassert(isequal(your_fcn_name(x),y_correct));","published":true,"deleted":false,"likes_count":4,"comments_count":1,"created_by":17203,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":166,"test_suite_updated_at":"2014-06-17T20:20:00.000Z","rescore_all_solutions":false,"group_id":31,"created_at":"2014-06-17T20:16:19.000Z","updated_at":"2026-02-18T18:06:51.000Z","published_at":"2014-06-17T20:20:00.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor a given odd integer n, generate a matrix as follows:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eInput: n = 5; Output:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ [ 2 1 0 0 0\\n 1 1 1 0 0\\n 0 1 0 1 0\\n 0 0 1 1 1\\n 0 0 0 1 2 ]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eInput: n=7; Output:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ [ 3 1 0 0 0 0 0\\n 1 2 1 0 0 0 0\\n 0 1 1 1 0 0 0\\n 0 0 1 0 1 0 0\\n 0 0 0 1 1 1 0\\n 0 0 0 0 1 2 1\\n 0 0 0 0 0 1 3 ]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor further understanding of the pattern, please check the test suite.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":859,"title":"Get the elements of diagonal and antidiagonal for any m-by-n matrix ","description":"In the problem \u003chttp://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal Problem 858. Permute diagonal and antidiagonal\u003e created by \u003chttp://www.mathworks.com/matlabcentral/cody/players/343082-jean-marie-sainthillier Jean-Marie SAINTHILLIER\u003e the test suite is only based on squared m-by-m matrix .\r\n\r\nIn this problem you must submit a solution which *returns the diagonal and anti-diagonal elements without using the DIAG function* for any *m-by-n matrix* \r\n\r\nExample:\r\n\r\nIf the input is a matrix 4*3\r\n\r\n x = [ 0 0 0\r\n 1 48 17\r\n 0 2 99\r\n 14 0 3]\r\n\r\nwe expect *2 output vectors*:\r\n\r\n dg_elements = [0 48 99] % diagonal elements\r\n\r\n antidg_elements = [14 2 17 ] % anti-diagonal elements\r\n\r\n\r\nNote : You do not have to permute anything. Just return the elements.","description_html":"\u003cp\u003eIn the problem \u003ca href=\"http://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal\"\u003eProblem 858. Permute diagonal and antidiagonal\u003c/a\u003e created by \u003ca href=\"http://www.mathworks.com/matlabcentral/cody/players/343082-jean-marie-sainthillier\"\u003eJean-Marie SAINTHILLIER\u003c/a\u003e the test suite is only based on squared m-by-m matrix .\u003c/p\u003e\u003cp\u003eIn this problem you must submit a solution which \u003cb\u003ereturns the diagonal and anti-diagonal elements without using the DIAG function\u003c/b\u003e for any \u003cb\u003em-by-n matrix\u003c/b\u003e\u003c/p\u003e\u003cp\u003eExample:\u003c/p\u003e\u003cp\u003eIf the input is a matrix 4*3\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003ex = [ 0 0 0\r\n 1 48 17\r\n 0 2 99\r\n 14 0 3]\r\n\u003c/pre\u003e\u003cp\u003ewe expect \u003cb\u003e2 output vectors\u003c/b\u003e:\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003edg_elements = [0 48 99] % diagonal elements\r\n\u003c/pre\u003e\u003cpre class=\"language-matlab\"\u003eantidg_elements = [14 2 17 ] % anti-diagonal elements\r\n\u003c/pre\u003e\u003cp\u003eNote : You do not have to permute anything. Just return the elements.\u003c/p\u003e","function_template":"function [dg_elements,antidg_elements] = your_fcn_name(x)\r\n dg_elements = 1 :8\r\n antidg_elements = 8:-1:1\r\nend","test_suite":"%% no diag\r\nfiletext = fileread('your_fcn_name.m');\r\nassert(isempty(strfind(filetext, 'diag')))\r\n\r\n%% square m-by-m matrix (1)\r\nx = [10 20 30; 40 50 60; 70 80 90];\r\ndiag_correct = [10 50 90];\r\nantidiag_correct = [ 70 50 30];\r\n[A,B]= your_fcn_name(x);\r\nassert(isequal(A,diag_correct))\r\nassert(isequal(B,antidiag_correct))\r\n\r\n\r\n%% m-by-n matrix where m \u003e= n (2)\r\nx = [10 20 30; 40 50 60 ; 70 80 90; 100 74 15];\r\ndiag_corrct78 = [10 50 90];\r\nantidiag_corrct78 = [ 100 80 60];\r\n[A3,B3]= your_fcn_name(x);\r\nassert(isequal(A3,diag_corrct78))\r\nassert(isequal(B3,antidiag_corrct78))\r\n\r\n\r\n%% m-by-n matrix where m \u003c= n (3)\r\nx = [10 20 30 58; 40 50 60 68 ; 70 80 90 98];\r\ndiag_correct7 = [10 50 90];\r\nantidiag_correct7 = [ 70 50 30];\r\n[A3,B3]= your_fcn_name(x);\r\nassert(isequal(A3,diag_correct7))\r\nassert(isequal(B3,antidiag_correct7))\r\n\r\n%% m-by-n matrix where m \u003e= n (4)\r\nt = [0 0 0; 1 0 0 ; 0 2 0; 0 0 3];\r\ndiag8 = [0 0 0];\r\nantid7 = [ 0 2 0];\r\n[A3,B3]= your_fcn_name(t);\r\nassert(isequal(A3,diag8))\r\nassert(isequal(B3,antid7))\r\n\r\n\r\n% m-by-n matrix where m \u003c= n (5)\r\nt = [0 1 0 0; 0 0 2 0 ; 0 0 0 3];\r\ndiag8 = [0 0 0];\r\nantid7 = [ 0 0 0];\r\n[A3,B3]= your_fcn_name(t);\r\nassert(isequal(A3,diag8))\r\nassert(isequal(B3,antid7))","published":true,"deleted":false,"likes_count":11,"comments_count":2,"created_by":639,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":513,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":12,"created_at":"2012-07-24T07:26:53.000Z","updated_at":"2026-02-10T12:04:49.000Z","published_at":"2012-07-24T07:26:53.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIn the problem\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 858. Permute diagonal and antidiagonal\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e created by\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/players/343082-jean-marie-sainthillier\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJean-Marie SAINTHILLIER\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e the test suite is only based on squared m-by-m matrix .\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIn this problem you must submit a solution which\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003ereturns the diagonal and anti-diagonal elements without using the DIAG function\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e for any\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003em-by-n matrix\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIf the input is a matrix 4*3\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[x = [ 0 0 0\\n 1 48 17\\n 0 2 99\\n 14 0 3]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ewe expect\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e2 output vectors\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[dg_elements = [0 48 99] % diagonal elements\\n\\nantidg_elements = [14 2 17 ] % anti-diagonal elements]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNote : You do not have to permute anything. Just return the elements.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2587,"title":"Find indices of diagonal elements","description":"Given a matrix A and a diagonal index d (where 0 indicates the main diagonal and off-diagonals are identified by positive and negative integers), return the indices of the elements of this diagonal. \r\n\r\nd is always correct but A can contain repetitions, so ...\r\n","description_html":"\u003cp\u003eGiven a matrix A and a diagonal index d (where 0 indicates the main diagonal and off-diagonals are identified by positive and negative integers), return the indices of the elements of this diagonal.\u003c/p\u003e\u003cp\u003ed is always correct but A can contain repetitions, so ...\u003c/p\u003e","function_template":"function y = diag_indices(A,d)\r\n y = d;\r\nend","test_suite":"%%\r\nx = [1 2 3;4 5 6;7 8 9];\r\na = [1 5 9];\r\nassert(isequal(diag_indices(x,0),a))\r\n%%\r\nx = magic(5);\r\nb = 5;\r\nassert(isequal(diag_indices(x,-4),b))\r\n%%\r\nx = magic(5);\r\na = 21;\r\nassert(isequal(diag_indices(x,4),a))\r\n%%\r\nx = magic(5);\r\nz = 5;\r\nassert(isequal(diag_indices(x,-4),z))\r\n%%\r\nx = magic(6);\r\na = [19 26 33];\r\nassert(isequal(diag_indices(x,3),a))\r\n%%\r\nx1 = magic(50);\r\ny_correct = 50;\r\nassert(isequal(diag_indices(x1,-49),y_correct))\r\n%%\r\nx2 = magic(50);\r\ny_correct = [49 100];\r\nassert(isequal(diag_indices(x2,-48),y_correct))\r\n%%\r\ny = magic(50);\r\nv = [48 99 150];\r\nassert(isequal(diag_indices(y,-47),v))\r\n%%\r\nv=[1 2 3;4 5 6;1 2 3];\r\nt = [1 5 9];\r\nassert(isequal(diag_indices(v,0),t))\r\n%%\r\nx=[1 2;1 2];\r\ny_correct = 3;\r\nassert(isequal(diag_indices(x,1),y_correct))\r\n%%\r\nx=[1 1 1;1 1 1;1 1 1];\r\nt = [1 5 9];\r\nassert(isequal(diag_indices(x,0),t))\r\n%%\r\ny=[1 2 3;1 2 3];\r\ny_correct = [1 4];\r\nassert(isequal(diag_indices(y,0),y_correct))\r\n","published":true,"deleted":false,"likes_count":2,"comments_count":2,"created_by":5390,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":73,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":39,"created_at":"2014-09-15T11:37:21.000Z","updated_at":"2026-04-02T08:13:56.000Z","published_at":"2014-09-15T11:38:07.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven a matrix A and a diagonal index d (where 0 indicates the main diagonal and off-diagonals are identified by positive and negative integers), return the indices of the elements of this diagonal.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ed is always correct but A can contain repetitions, so ...\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":858,"title":"Permute diagonal and antidiagonal","description":"Permute diagonal and antidiagonal\r\nFor example [1 2 3;4 5 6;7 8 9] -\u003e [3 2 1;4 5 6;9 8 7]\r\nWITHOUT diag function (and variable name)\r\n","description_html":"\u003cp\u003ePermute diagonal and antidiagonal\r\nFor example [1 2 3;4 5 6;7 8 9] -\u003e [3 2 1;4 5 6;9 8 7]\r\nWITHOUT diag function (and variable name)\u003c/p\u003e","function_template":"function y = permuted(x)\r\n y = withoutdiag(x);\r\nend","test_suite":"%%\r\nx = [1 2 3;4 5 6;7 8 9];\r\ny_correct = [3 2 1;4 5 6;9 8 7];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n%%\r\nx=[1 2;3 4];\r\ny_correct = [2 1;4 3];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n%%\r\nx=[1 2;3 4];\r\ny_correct = [2 1;4 3];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n%%\r\nx=magic(10);\r\ny_correct = [ 40 99 1 8 15 67 74 51 58 92\r\n 98 64 7 14 16 73 55 57 80 41\r\n 4 81 63 20 22 54 56 88 70 47\r\n 85 87 19 62 3 60 21 69 71 28\r\n 86 93 25 2 61 9 68 75 52 34\r\n 17 24 76 83 42 90 49 26 33 65\r\n 23 5 82 30 91 48 89 32 39 66\r\n 79 6 38 95 97 29 31 13 45 72\r\n 10 46 94 96 78 35 37 44 12 53\r\n 59 18 100 77 84 36 43 50 27 11];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":7,"comments_count":1,"created_by":5390,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":505,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":19,"created_at":"2012-07-24T01:19:14.000Z","updated_at":"2026-04-02T19:11:56.000Z","published_at":"2012-07-24T01:19:14.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePermute diagonal and antidiagonal For example [1 2 3;4 5 6;7 8 9] -\u003e [3 2 1;4 5 6;9 8 7] WITHOUT diag function (and variable name)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":45578,"title":"Create a matrix that counts up diagonally","description":"Given a single input _N_, create a _N_ x _N_ matrix that counts from 1 : _N_ ², (along up-right diagonals, starting with 1 in the top left corner. For example, given N=4...\r\n\r\n 1 3 6 10\r\n 2 5 9 13 \r\n 4 8 12 15 \r\n 7 11 14 16\r\n \r\n\r\nNotice as you move up a row and right a column (↗) the values always increase by one. The value '1' should always go in the top left corner, with '2' directly below it. From there fill in the upward-rightward diagonals with the next higher integer until the matrix is complete. Assume N will always be a positive integer greater than 1 (N \u003e= 2).\r\n","description_html":"\u003cp\u003eGiven a single input \u003ci\u003eN\u003c/i\u003e, create a \u003ci\u003eN\u003c/i\u003e x \u003ci\u003eN\u003c/i\u003e matrix that counts from 1 : \u003ci\u003eN\u003c/i\u003e ², (along up-right diagonals, starting with 1 in the top left corner. For example, given N=4...\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003e1 3 6 10\r\n2 5 9 13 \r\n4 8 12 15 \r\n7 11 14 16\r\n\u003c/pre\u003e\u003cp\u003eNotice as you move up a row and right a column (↗) the values always increase by one. The value '1' should always go in the top left corner, with '2' directly below it. From there fill in the upward-rightward diagonals with the next higher integer until the matrix is complete. Assume N will always be a positive integer greater than 1 (N \u0026gt;= 2).\u003c/p\u003e","function_template":"function mx = not_hankel(N)\r\n\r\n mx = ones(N); %replace with your code\r\n\r\nend","test_suite":"%%\r\nN = 20;\r\n\r\nmx_correct = [...\r\n 1 3 6 10 15 21 28 36 45 55 66 78 91 105 120 136 153 171 190 210\r\n 2 5 9 14 20 27 35 44 54 65 77 90 104 119 135 152 170 189 209 229\r\n 4 8 13 19 26 34 43 53 64 76 89 103 118 134 151 169 188 208 228 247\r\n 7 12 18 25 33 42 52 63 75 88 102 117 133 150 168 187 207 227 246 264\r\n 11 17 24 32 41 51 62 74 87 101 116 132 149 167 186 206 226 245 263 280\r\n 16 23 31 40 50 61 73 86 100 115 131 148 166 185 205 225 244 262 279 295\r\n 22 30 39 49 60 72 85 99 114 130 147 165 184 204 224 243 261 278 294 309\r\n 29 38 48 59 71 84 98 113 129 146 164 183 203 223 242 260 277 293 308 322\r\n 37 47 58 70 83 97 112 128 145 163 182 202 222 241 259 276 292 307 321 334\r\n 46 57 69 82 96 111 127 144 162 181 201 221 240 258 275 291 306 320 333 345\r\n 56 68 81 95 110 126 143 161 180 200 220 239 257 274 290 305 319 332 344 355\r\n 67 80 94 109 125 142 160 179 199 219 238 256 273 289 304 318 331 343 354 364\r\n 79 93 108 124 141 159 178 198 218 237 255 272 288 303 317 330 342 353 363 372\r\n 92 107 123 140 158 177 197 217 236 254 271 287 302 316 329 341 352 362 371 379\r\n 106 122 139 157 176 196 216 235 253 270 286 301 315 328 340 351 361 370 378 385\r\n 121 138 156 175 195 215 234 252 269 285 300 314 327 339 350 360 369 377 384 390\r\n 137 155 174 194 214 233 251 268 284 299 313 326 338 349 359 368 376 383 389 394\r\n 154 173 193 213 232 250 267 283 298 312 325 337 348 358 367 375 382 388 393 397\r\n 172 192 212 231 249 266 282 297 311 324 336 347 357 366 374 381 387 392 396 399\r\n 191 211 230 248 265 281 296 310 323 335 346 356 365 373 380 386 391 395 398 400\r\n ];\r\n\r\nassert(isequal(not_hankel(N),mx_correct))\r\n\r\n\r\n\r\n%%\r\nN = 3;\r\n\r\nmx_correct = [...\r\n 1 3 6\r\n 2 5 8\r\n 4 7 9\r\n ];\r\n\r\nassert(isequal(not_hankel(N),mx_correct))\r\n\r\n\r\n\r\n%%\r\nrng('shuffle')\r\nN = randi(99)+5;\r\nr = repmat((0:(N-1))',1,N) + (0:(N-1));\r\np = ((.5.*r.^2 + .5.*r) + (r(1,:)+1));\r\nq = rot90(hankel(fliplr(0:N-1)),2).^2;\r\nmx_correct = p - q;\r\nassert(isequal(not_hankel(N),mx_correct))\r\n\r\n\r\n\r\n%% \r\nN = 2;\r\nmx_correct =...\r\n[...\r\n 1 3\r\n 2 4 \r\n];\r\n\r\nassert(isequal(not_hankel(N),mx_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":18354,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":22,"test_suite_updated_at":"2020-05-22T17:05:13.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2020-05-22T16:46:56.000Z","updated_at":"2026-01-20T13:24:26.000Z","published_at":"2020-05-22T16:46:56.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven a single input\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e, create a\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e x\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e matrix that counts from 1 :\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e ², (along up-right diagonals, starting with 1 in the top left corner. For example, given N=4...\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[1 3 6 10\\n2 5 9 13 \\n4 8 12 15 \\n7 11 14 16]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNotice as you move up a row and right a column (↗) the values always increase by one. The value '1' should always go in the top left corner, with '2' directly below it. From there fill in the upward-rightward diagonals with the next higher integer until the matrix is complete. Assume N will always be a positive integer greater than 1 (N \u0026gt;= 2).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2455,"title":"Diagonal of a Spiral Matrix","description":"Write a function that will return same output as diag(spiral(n)). The only exception is that spiral and diag functions are not allowed in your function. Also, loops are not allowed.","description_html":"\u003cp\u003eWrite a function that will return same output as diag(spiral(n)). The only exception is that spiral and diag functions are not allowed in your function. Also, loops are not allowed.\u003c/p\u003e","function_template":"function y=digSpi(n)\r\n\r\n\r\n\r\n\r\nend","test_suite":"s = evalc('type digSpi');\r\n\r\nif ~isempty(regexp(s,'error'))\r\n error('error using error');\r\nend\r\n\r\nif ~isempty(regexp(s,'assert'))\r\n error('error using assert');\r\nend\r\n\r\nif ~isempty(regexp(s,'diag'))\r\n error('error using diag');\r\nend\r\n\r\nif ~isempty(regexp(s,'spiral'))\r\n error('error using spiral');\r\nend\r\n\r\nif ~isempty(regexp(s,'for'))\r\n error('error using for');\r\nend\r\n\r\nif ~isempty(regexp(s,'while'))\r\n error('error using while');\r\nend\r\n\r\n%%\r\n\r\na = diag(spiral(4));\r\nb = digSpi(4);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(5));\r\nb = digSpi(5);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(6));\r\nb = digSpi(6);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(7));\r\nb = digSpi(7);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(8));\r\nb = digSpi(8);\r\nassert(isequal(a,b));","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":17203,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":111,"test_suite_updated_at":"2014-07-21T18:30:07.000Z","rescore_all_solutions":false,"group_id":31,"created_at":"2014-07-20T08:15:09.000Z","updated_at":"2026-03-04T17:27:33.000Z","published_at":"2014-07-20T08:15:09.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWrite a function that will return same output as diag(spiral(n)). The only exception is that spiral and diag functions are not allowed in your function. Also, loops are not allowed.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":59242,"title":"Construct numbers from antidiagonals of stacks of binary numbers","description":"A sequence is constructed in the following way: Express the numbers 1, 2, 3, 4, 5,… in binary and stack them, right-justified. Then read the numbers in upward sloping diagonals and convert to decimal. The first four binary numbers are 11, 110, 101, 100, and their decimal equivalents are 3, 6, 5, 4. \r\n0 0 0 1\r\n0 0 1 0 \r\n0 0 1 1 \r\n0 1 0 0\r\n0 1 0 1\r\n0 1 1 0 \r\nWrite a function to compute the th term in the sequence. ","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 273px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 136.5px; transform-origin: 407px 136.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 384px 8px; transform-origin: 384px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eA sequence is constructed in the following way: Express the numbers 1, 2, 3, 4, 5,… in binary and stack them, right-justified. Then read the numbers in upward sloping diagonals and convert to decimal. The first four binary numbers are 11, 110, 101, 100, and their decimal equivalents are 3, 6, 5, 4. \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.95px 8px; transform-origin: 26.95px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 0 0 1\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 30.8px 8px; transform-origin: 30.8px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 0 1 0 \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 30.8px 8px; transform-origin: 30.8px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 0 1 1 \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.95px 8px; transform-origin: 26.95px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 1 0 0\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.95px 8px; transform-origin: 26.95px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 1 0 1\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 30.8px 8px; transform-origin: 30.8px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 1 1 0 \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 98.6583px 8px; transform-origin: 98.6583px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eWrite a function to compute the \u003c/span\u003e\u003c/span\u003e\u003cspan style=\"font-family: \u0026quot;STIXGeneral\u0026quot;, \u0026quot;STIXGeneral-webfont\u0026quot;, serif; font-style: italic; font-weight: 400; color: rgb(0, 0, 0);\"\u003en\u003c/span\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 77.0083px 8px; transform-origin: 77.0083px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eth term in the sequence. \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = slopingBinary(n)\r\n y = diag(dec2bin(1:n)');\r\nend","test_suite":"%%\r\nn = 4;\r\ny_correct = 4;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 12;\r\ny_correct = 28;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 27;\r\ny_correct = 61;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 59;\r\ny_correct = 93;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 122;\r\ny_correct = 190;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 249;\r\ny_correct = 379;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 1015;\r\ny_correct = 1529;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 2038;\r\ny_correct = 3066;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 4085;\r\ny_correct = 6143;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 8180;\r\ny_correct = 12276;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 16537;\r\ny_correct = 16539;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 485373;\r\ny_correct = 485383;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 7341901;\r\ny_correct = 7341911;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 55988359;\r\ny_correct = 55988361;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 1073741824;\r\nassert(isequal(slopingBinary(n),n))\r\n\r\n%%\r\nn = 17179869184;\r\nassert(isequal(slopingBinary(n),n))\r\n\r\n%%\r\nassert(isequal(slopingBinary(flintmax/2),flintmax/2))\r\n\r\n%%\r\nn = 899423417;\r\nyyyy_correct = 899423465;\r\ny = slopingBinary(slopingBinary(slopingBinary(slopingBinary(n))));\r\nassert(isequal(y,yyyy_correct))\r\n\r\n%%\r\nfiletext = fileread('slopingBinary.m');\r\nillegal = contains(filetext, 'assignin') || contains(filetext, 'assert') || contains(filetext,'regexp'); \r\nassert(~illegal)","published":true,"deleted":false,"likes_count":1,"comments_count":2,"created_by":46909,"edited_by":46909,"edited_at":"2023-11-28T03:00:34.000Z","deleted_by":null,"deleted_at":null,"solvers_count":5,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2023-11-28T03:00:26.000Z","updated_at":"2023-11-28T03:00:34.000Z","published_at":"2023-11-28T03:00:34.000Z","restored_at":null,"restored_by":null,"spam":null,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eA sequence is constructed in the following way: Express the numbers 1, 2, 3, 4, 5,… in binary and stack them, right-justified. Then read the numbers in upward sloping diagonals and convert to decimal. The first four binary numbers are 11, 110, 101, 100, and their decimal equivalents are 3, 6, 5, 4. \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 0 0 1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 0 1 0 \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 0 1 1 \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 1 0 0\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 1 0 1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 1 1 0 \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWrite a function to compute the \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:customXml w:element=\\\"equation\\\"\u003e\u003cw:customXmlPr\u003e\u003cw:attr w:name=\\\"displayStyle\\\" w:val=\\\"false\\\"/\u003e\u003cw:attr w:name=\\\"altTextString\\\" w:val=\\\"n\\\"/\u003e\u003c/w:customXmlPr\u003e\u003cw:r\u003e\u003cw:t\u003en\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:customXml\u003e\u003cw:r\u003e\u003cw:t\u003eth term in the sequence. \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":2585,"title":"How to reverse spdiags?","description":"The spdiags function extracts all nonzero diagonals from the m-by-n matrix A.\r\n\r\nSo if A=[1 2 3;4 5 6;7 8 9],\r\n\r\nspdiags(A)=[7 4 1 0 0;0 8 5 2 0;0 0 9 6 3].\r\n\r\nBut if I give you spdiags(A), can you give me A ?","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.44px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: none solid rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 213px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 332px 106.5px; transform-origin: 332px 106.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003eThe spdiags function extracts all nonzero diagonals from the m-by-n matrix A.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003eSo if\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgb(247, 247, 247); block-size: 20px; border-bottom-left-radius: 4px; border-bottom-right-radius: 4px; border-top-left-radius: 4px; border-top-right-radius: 4px; margin-block-end: 10px; margin-block-start: 10px; margin-bottom: 10px; margin-inline-end: 3px; margin-inline-start: 3px; margin-left: 3px; margin-right: 3px; margin-top: 10px; perspective-origin: 329px 10px; transform-origin: 329px 10px; margin-left: 3px; margin-top: 10px; margin-bottom: 10px; margin-right: 3px; \"\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e A = [1 2 3;4 5 6;7 8 9]\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 10px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 10px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 10px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003ethen\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgb(247, 247, 247); block-size: 60px; border-bottom-left-radius: 4px; border-bottom-right-radius: 4px; border-top-left-radius: 4px; border-top-right-radius: 4px; margin-block-end: 10px; margin-block-start: 10px; margin-bottom: 10px; margin-inline-end: 3px; margin-inline-start: 3px; margin-left: 3px; margin-right: 3px; margin-top: 10px; perspective-origin: 329px 30px; transform-origin: 329px 30px; margin-left: 3px; margin-top: 10px; margin-bottom: 10px; margin-right: 3px; \"\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 329px 10px; transform-origin: 329px 10px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e spdiags(A) = [7 4 1 0 0;\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 329px 10px; transform-origin: 329px 10px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e 0 8 5 2 0;\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 329px 10px; transform-origin: 329px 10px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e 0 0 9 6 3]\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 10px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 10px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 10px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003eBut if I give you spdiags(A), can you give me A ?\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = inv_spdiags(x)\r\n y = x;\r\nend","test_suite":"%%\r\nx = spdiags([1 2 3;4 5 6;7 8 9]);\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\nb = spdiags(eye(10));\r\nassert(isequal(spdiags(inv_spdiags(b)),b))\r\n%%\r\nx = spdiags([1 2 3;4 5 6]);\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\ny = spdiags(magic(9));\r\nassert(isequal(spdiags(inv_spdiags(y)),y))\r\n%%\r\nx = spdiags(magic(5));\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\nz = spdiags(ones(10));\r\nassert(isequal(spdiags(inv_spdiags(z)),z))\r\n%%\r\nx = spdiags(randi(10,5));\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\nx = spdiags(randi(5,[3 2]));\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\na = spdiags(zeros(5));\r\nassert(isequal(spdiags(inv_spdiags(a)),a))","published":true,"deleted":false,"likes_count":2,"comments_count":1,"created_by":5390,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":43,"test_suite_updated_at":"2014-09-14T14:43:49.000Z","rescore_all_solutions":false,"group_id":39,"created_at":"2014-09-14T14:39:28.000Z","updated_at":"2026-02-15T11:51:56.000Z","published_at":"2014-09-14T14:41:28.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThe spdiags function extracts all nonzero diagonals from the m-by-n matrix A.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eSo if\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ A = [1 2 3;4 5 6;7 8 9]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ethen\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ spdiags(A) = [7 4 1 0 0;\\n 0 8 5 2 0;\\n 0 0 9 6 3]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eBut if I give you spdiags(A), can you give me A ?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"}],"problem_search":{"errors":[],"problems":[{"id":46888,"title":"Diagonal Prod","description":null,"description_html":"\u003cdiv style = \"text-align: start; line-height: 20.44px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: none solid rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 20.8px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 10.4px; transform-origin: 407px 10.4px; vertical-align: baseline; \"\u003e\u003cdiv style=\"font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.4px; text-align: left; transform-origin: 384px 10.4px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003ereturn element by element product of two diagonal vectors of two matrixes\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = your_fcn_name(x)\r\n y = x;\r\nend","test_suite":"%%\r\nx = ones(3);\r\nz=zeros(3);\r\ny_correct = [0 0 0];\r\nassert(isequal(your_fcn_name(x,z),y_correct))\r\n\r\n%%\r\nx = ones(3);\r\nz=magic(3);\r\ny_correct = [8 5 2];\r\nassert(isequal(your_fcn_name(x,z),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":430136,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":90,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-10-17T15:43:56.000Z","updated_at":"2026-03-31T15:17:22.000Z","published_at":"2020-10-17T15:43:56.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ereturn element by element product of two diagonal vectors of two matrixes\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":1158,"title":"Sum the elements in either diagonal of a square matrix","description":"Sum the elements of a square matrix that lie on either the major diagonal or anti-diagonal. (Include all elements that are part of either of the diagonals).","description_html":"\u003cp\u003eSum the elements of a square matrix that lie on either the major diagonal or anti-diagonal. (Include all elements that are part of either of the diagonals).\u003c/p\u003e","function_template":"function y = sumDiagonalElements(x)\r\n y = 0;\r\nend","test_suite":"%%\r\nx = ones(2);\r\ny_correct = 4;\r\nassert(isequal(sumDiagonalElements(x),y_correct))\r\n%%\r\nx = ones(3);\r\ny_correct = 5;\r\nassert(isequal(sumDiagonalElements(x),y_correct))\r\n%%\r\nx = magic(8);\r\ny_correct = 520;\r\nassert(isequal(sumDiagonalElements(x),y_correct))\r\n%%\r\nx = magic(9);\r\ny_correct = 697;\r\nassert(isequal(sumDiagonalElements(x),y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":3,"created_by":8780,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":221,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2012-12-31T21:51:27.000Z","updated_at":"2026-02-09T20:24:17.000Z","published_at":"2012-12-31T21:53:05.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eSum the elements of a square matrix that lie on either the major diagonal or anti-diagonal. (Include all elements that are part of either of the diagonals).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2365,"title":"Generate this matrix","description":"For a given odd integer n, generate a matrix as follows:\r\n\r\nInput: n = 5;\r\nOutput:\r\n \r\n\r\n [ 2 1 0 0 0\r\n 1 1 1 0 0\r\n 0 1 0 1 0\r\n 0 0 1 1 1\r\n 0 0 0 1 2 ]\r\n\r\n\r\nInput: n=7;\r\nOutput:\r\n \r\n\r\n [ 3 1 0 0 0 0 0\r\n 1 2 1 0 0 0 0\r\n 0 1 1 1 0 0 0\r\n 0 0 1 0 1 0 0\r\n 0 0 0 1 1 1 0\r\n 0 0 0 0 1 2 1\r\n 0 0 0 0 0 1 3 ]\r\n\r\nFor further understanding of the pattern, please check the test suite.","description_html":"\u003cp\u003eFor a given odd integer n, generate a matrix as follows:\u003c/p\u003e\u003cp\u003eInput: n = 5;\r\nOutput:\u003c/p\u003e\u003cpre\u003e [ 2 1 0 0 0\r\n 1 1 1 0 0\r\n 0 1 0 1 0\r\n 0 0 1 1 1\r\n 0 0 0 1 2 ]\u003c/pre\u003e\u003cp\u003eInput: n=7;\r\nOutput:\u003c/p\u003e\u003cpre\u003e [ 3 1 0 0 0 0 0\r\n 1 2 1 0 0 0 0\r\n 0 1 1 1 0 0 0\r\n 0 0 1 0 1 0 0\r\n 0 0 0 1 1 1 0\r\n 0 0 0 0 1 2 1\r\n 0 0 0 0 0 1 3 ]\u003c/pre\u003e\u003cp\u003eFor further understanding of the pattern, please check the test suite.\u003c/p\u003e","function_template":"function y = your_fcn_name(x)\r\n\r\nend","test_suite":"%%\r\nx = 7;\r\ny_correct = [3 1 0 0 0 0 0;\r\n 1 2 1 0 0 0 0;\r\n 0 1 1 1 0 0 0;\r\n 0 0 1 0 1 0 0;\r\n 0 0 0 1 1 1 0;\r\n 0 0 0 0 1 2 1;\r\n 0 0 0 0 0 1 3];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n\r\n%%\r\nx = 5;\r\ny_correct =[2 1 0 0 0;\r\n 1 1 1 0 0;\r\n 0 1 0 1 0;\r\n 0 0 1 1 1;\r\n 0 0 0 1 2];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n\r\n%%\r\nx = 11;\r\ny_correct =[5 1 0 0 0 0 0 0 0 0 0;\r\n 1 4 1 0 0 0 0 0 0 0 0;\r\n 0 1 3 1 0 0 0 0 0 0 0;\r\n 0 0 1 2 1 0 0 0 0 0 0;\r\n 0 0 0 1 1 1 0 0 0 0 0;\r\n 0 0 0 0 1 0 1 0 0 0 0;\r\n 0 0 0 0 0 1 1 1 0 0 0;\r\n 0 0 0 0 0 0 1 2 1 0 0;\r\n 0 0 0 0 0 0 0 1 3 1 0;\r\n 0 0 0 0 0 0 0 0 1 4 1;\r\n 0 0 0 0 0 0 0 0 0 1 5];\r\nassert(isequal(your_fcn_name(x),y_correct));\r\n\r\n%%\r\nx = 5;\r\ny_correct =[2 1 0 0 0;\r\n 1 1 1 0 0;\r\n 0 1 0 1 0;\r\n 0 0 1 1 1;\r\n 0 0 0 1 2];\r\nassert(isequal(your_fcn_name(x),y_correct));","published":true,"deleted":false,"likes_count":4,"comments_count":1,"created_by":17203,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":166,"test_suite_updated_at":"2014-06-17T20:20:00.000Z","rescore_all_solutions":false,"group_id":31,"created_at":"2014-06-17T20:16:19.000Z","updated_at":"2026-02-18T18:06:51.000Z","published_at":"2014-06-17T20:20:00.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor a given odd integer n, generate a matrix as follows:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eInput: n = 5; Output:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ [ 2 1 0 0 0\\n 1 1 1 0 0\\n 0 1 0 1 0\\n 0 0 1 1 1\\n 0 0 0 1 2 ]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eInput: n=7; Output:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ [ 3 1 0 0 0 0 0\\n 1 2 1 0 0 0 0\\n 0 1 1 1 0 0 0\\n 0 0 1 0 1 0 0\\n 0 0 0 1 1 1 0\\n 0 0 0 0 1 2 1\\n 0 0 0 0 0 1 3 ]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor further understanding of the pattern, please check the test suite.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":859,"title":"Get the elements of diagonal and antidiagonal for any m-by-n matrix ","description":"In the problem \u003chttp://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal Problem 858. Permute diagonal and antidiagonal\u003e created by \u003chttp://www.mathworks.com/matlabcentral/cody/players/343082-jean-marie-sainthillier Jean-Marie SAINTHILLIER\u003e the test suite is only based on squared m-by-m matrix .\r\n\r\nIn this problem you must submit a solution which *returns the diagonal and anti-diagonal elements without using the DIAG function* for any *m-by-n matrix* \r\n\r\nExample:\r\n\r\nIf the input is a matrix 4*3\r\n\r\n x = [ 0 0 0\r\n 1 48 17\r\n 0 2 99\r\n 14 0 3]\r\n\r\nwe expect *2 output vectors*:\r\n\r\n dg_elements = [0 48 99] % diagonal elements\r\n\r\n antidg_elements = [14 2 17 ] % anti-diagonal elements\r\n\r\n\r\nNote : You do not have to permute anything. Just return the elements.","description_html":"\u003cp\u003eIn the problem \u003ca href=\"http://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal\"\u003eProblem 858. Permute diagonal and antidiagonal\u003c/a\u003e created by \u003ca href=\"http://www.mathworks.com/matlabcentral/cody/players/343082-jean-marie-sainthillier\"\u003eJean-Marie SAINTHILLIER\u003c/a\u003e the test suite is only based on squared m-by-m matrix .\u003c/p\u003e\u003cp\u003eIn this problem you must submit a solution which \u003cb\u003ereturns the diagonal and anti-diagonal elements without using the DIAG function\u003c/b\u003e for any \u003cb\u003em-by-n matrix\u003c/b\u003e\u003c/p\u003e\u003cp\u003eExample:\u003c/p\u003e\u003cp\u003eIf the input is a matrix 4*3\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003ex = [ 0 0 0\r\n 1 48 17\r\n 0 2 99\r\n 14 0 3]\r\n\u003c/pre\u003e\u003cp\u003ewe expect \u003cb\u003e2 output vectors\u003c/b\u003e:\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003edg_elements = [0 48 99] % diagonal elements\r\n\u003c/pre\u003e\u003cpre class=\"language-matlab\"\u003eantidg_elements = [14 2 17 ] % anti-diagonal elements\r\n\u003c/pre\u003e\u003cp\u003eNote : You do not have to permute anything. Just return the elements.\u003c/p\u003e","function_template":"function [dg_elements,antidg_elements] = your_fcn_name(x)\r\n dg_elements = 1 :8\r\n antidg_elements = 8:-1:1\r\nend","test_suite":"%% no diag\r\nfiletext = fileread('your_fcn_name.m');\r\nassert(isempty(strfind(filetext, 'diag')))\r\n\r\n%% square m-by-m matrix (1)\r\nx = [10 20 30; 40 50 60; 70 80 90];\r\ndiag_correct = [10 50 90];\r\nantidiag_correct = [ 70 50 30];\r\n[A,B]= your_fcn_name(x);\r\nassert(isequal(A,diag_correct))\r\nassert(isequal(B,antidiag_correct))\r\n\r\n\r\n%% m-by-n matrix where m \u003e= n (2)\r\nx = [10 20 30; 40 50 60 ; 70 80 90; 100 74 15];\r\ndiag_corrct78 = [10 50 90];\r\nantidiag_corrct78 = [ 100 80 60];\r\n[A3,B3]= your_fcn_name(x);\r\nassert(isequal(A3,diag_corrct78))\r\nassert(isequal(B3,antidiag_corrct78))\r\n\r\n\r\n%% m-by-n matrix where m \u003c= n (3)\r\nx = [10 20 30 58; 40 50 60 68 ; 70 80 90 98];\r\ndiag_correct7 = [10 50 90];\r\nantidiag_correct7 = [ 70 50 30];\r\n[A3,B3]= your_fcn_name(x);\r\nassert(isequal(A3,diag_correct7))\r\nassert(isequal(B3,antidiag_correct7))\r\n\r\n%% m-by-n matrix where m \u003e= n (4)\r\nt = [0 0 0; 1 0 0 ; 0 2 0; 0 0 3];\r\ndiag8 = [0 0 0];\r\nantid7 = [ 0 2 0];\r\n[A3,B3]= your_fcn_name(t);\r\nassert(isequal(A3,diag8))\r\nassert(isequal(B3,antid7))\r\n\r\n\r\n% m-by-n matrix where m \u003c= n (5)\r\nt = [0 1 0 0; 0 0 2 0 ; 0 0 0 3];\r\ndiag8 = [0 0 0];\r\nantid7 = [ 0 0 0];\r\n[A3,B3]= your_fcn_name(t);\r\nassert(isequal(A3,diag8))\r\nassert(isequal(B3,antid7))","published":true,"deleted":false,"likes_count":11,"comments_count":2,"created_by":639,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":513,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":12,"created_at":"2012-07-24T07:26:53.000Z","updated_at":"2026-02-10T12:04:49.000Z","published_at":"2012-07-24T07:26:53.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIn the problem\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 858. Permute diagonal and antidiagonal\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e created by\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/players/343082-jean-marie-sainthillier\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJean-Marie SAINTHILLIER\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e the test suite is only based on squared m-by-m matrix .\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIn this problem you must submit a solution which\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003ereturns the diagonal and anti-diagonal elements without using the DIAG function\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e for any\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003em-by-n matrix\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIf the input is a matrix 4*3\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[x = [ 0 0 0\\n 1 48 17\\n 0 2 99\\n 14 0 3]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ewe expect\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e2 output vectors\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[dg_elements = [0 48 99] % diagonal elements\\n\\nantidg_elements = [14 2 17 ] % anti-diagonal elements]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNote : You do not have to permute anything. Just return the elements.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2587,"title":"Find indices of diagonal elements","description":"Given a matrix A and a diagonal index d (where 0 indicates the main diagonal and off-diagonals are identified by positive and negative integers), return the indices of the elements of this diagonal. \r\n\r\nd is always correct but A can contain repetitions, so ...\r\n","description_html":"\u003cp\u003eGiven a matrix A and a diagonal index d (where 0 indicates the main diagonal and off-diagonals are identified by positive and negative integers), return the indices of the elements of this diagonal.\u003c/p\u003e\u003cp\u003ed is always correct but A can contain repetitions, so ...\u003c/p\u003e","function_template":"function y = diag_indices(A,d)\r\n y = d;\r\nend","test_suite":"%%\r\nx = [1 2 3;4 5 6;7 8 9];\r\na = [1 5 9];\r\nassert(isequal(diag_indices(x,0),a))\r\n%%\r\nx = magic(5);\r\nb = 5;\r\nassert(isequal(diag_indices(x,-4),b))\r\n%%\r\nx = magic(5);\r\na = 21;\r\nassert(isequal(diag_indices(x,4),a))\r\n%%\r\nx = magic(5);\r\nz = 5;\r\nassert(isequal(diag_indices(x,-4),z))\r\n%%\r\nx = magic(6);\r\na = [19 26 33];\r\nassert(isequal(diag_indices(x,3),a))\r\n%%\r\nx1 = magic(50);\r\ny_correct = 50;\r\nassert(isequal(diag_indices(x1,-49),y_correct))\r\n%%\r\nx2 = magic(50);\r\ny_correct = [49 100];\r\nassert(isequal(diag_indices(x2,-48),y_correct))\r\n%%\r\ny = magic(50);\r\nv = [48 99 150];\r\nassert(isequal(diag_indices(y,-47),v))\r\n%%\r\nv=[1 2 3;4 5 6;1 2 3];\r\nt = [1 5 9];\r\nassert(isequal(diag_indices(v,0),t))\r\n%%\r\nx=[1 2;1 2];\r\ny_correct = 3;\r\nassert(isequal(diag_indices(x,1),y_correct))\r\n%%\r\nx=[1 1 1;1 1 1;1 1 1];\r\nt = [1 5 9];\r\nassert(isequal(diag_indices(x,0),t))\r\n%%\r\ny=[1 2 3;1 2 3];\r\ny_correct = [1 4];\r\nassert(isequal(diag_indices(y,0),y_correct))\r\n","published":true,"deleted":false,"likes_count":2,"comments_count":2,"created_by":5390,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":73,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":39,"created_at":"2014-09-15T11:37:21.000Z","updated_at":"2026-04-02T08:13:56.000Z","published_at":"2014-09-15T11:38:07.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven a matrix A and a diagonal index d (where 0 indicates the main diagonal and off-diagonals are identified by positive and negative integers), return the indices of the elements of this diagonal.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ed is always correct but A can contain repetitions, so ...\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":858,"title":"Permute diagonal and antidiagonal","description":"Permute diagonal and antidiagonal\r\nFor example [1 2 3;4 5 6;7 8 9] -\u003e [3 2 1;4 5 6;9 8 7]\r\nWITHOUT diag function (and variable name)\r\n","description_html":"\u003cp\u003ePermute diagonal and antidiagonal\r\nFor example [1 2 3;4 5 6;7 8 9] -\u003e [3 2 1;4 5 6;9 8 7]\r\nWITHOUT diag function (and variable name)\u003c/p\u003e","function_template":"function y = permuted(x)\r\n y = withoutdiag(x);\r\nend","test_suite":"%%\r\nx = [1 2 3;4 5 6;7 8 9];\r\ny_correct = [3 2 1;4 5 6;9 8 7];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n%%\r\nx=[1 2;3 4];\r\ny_correct = [2 1;4 3];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n%%\r\nx=[1 2;3 4];\r\ny_correct = [2 1;4 3];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n%%\r\nx=magic(10);\r\ny_correct = [ 40 99 1 8 15 67 74 51 58 92\r\n 98 64 7 14 16 73 55 57 80 41\r\n 4 81 63 20 22 54 56 88 70 47\r\n 85 87 19 62 3 60 21 69 71 28\r\n 86 93 25 2 61 9 68 75 52 34\r\n 17 24 76 83 42 90 49 26 33 65\r\n 23 5 82 30 91 48 89 32 39 66\r\n 79 6 38 95 97 29 31 13 45 72\r\n 10 46 94 96 78 35 37 44 12 53\r\n 59 18 100 77 84 36 43 50 27 11];\r\nfiletext = fileread('permuted.m');\r\nassert(isequal(permuted(x),y_correct))\r\nassert(isempty(strfind(filetext, 'diag')))\r\n\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":7,"comments_count":1,"created_by":5390,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":505,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":19,"created_at":"2012-07-24T01:19:14.000Z","updated_at":"2026-04-02T19:11:56.000Z","published_at":"2012-07-24T01:19:14.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePermute diagonal and antidiagonal For example [1 2 3;4 5 6;7 8 9] -\u003e [3 2 1;4 5 6;9 8 7] WITHOUT diag function (and variable name)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":45578,"title":"Create a matrix that counts up diagonally","description":"Given a single input _N_, create a _N_ x _N_ matrix that counts from 1 : _N_ ², (along up-right diagonals, starting with 1 in the top left corner. For example, given N=4...\r\n\r\n 1 3 6 10\r\n 2 5 9 13 \r\n 4 8 12 15 \r\n 7 11 14 16\r\n \r\n\r\nNotice as you move up a row and right a column (↗) the values always increase by one. The value '1' should always go in the top left corner, with '2' directly below it. From there fill in the upward-rightward diagonals with the next higher integer until the matrix is complete. Assume N will always be a positive integer greater than 1 (N \u003e= 2).\r\n","description_html":"\u003cp\u003eGiven a single input \u003ci\u003eN\u003c/i\u003e, create a \u003ci\u003eN\u003c/i\u003e x \u003ci\u003eN\u003c/i\u003e matrix that counts from 1 : \u003ci\u003eN\u003c/i\u003e ², (along up-right diagonals, starting with 1 in the top left corner. For example, given N=4...\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003e1 3 6 10\r\n2 5 9 13 \r\n4 8 12 15 \r\n7 11 14 16\r\n\u003c/pre\u003e\u003cp\u003eNotice as you move up a row and right a column (↗) the values always increase by one. The value '1' should always go in the top left corner, with '2' directly below it. From there fill in the upward-rightward diagonals with the next higher integer until the matrix is complete. Assume N will always be a positive integer greater than 1 (N \u0026gt;= 2).\u003c/p\u003e","function_template":"function mx = not_hankel(N)\r\n\r\n mx = ones(N); %replace with your code\r\n\r\nend","test_suite":"%%\r\nN = 20;\r\n\r\nmx_correct = [...\r\n 1 3 6 10 15 21 28 36 45 55 66 78 91 105 120 136 153 171 190 210\r\n 2 5 9 14 20 27 35 44 54 65 77 90 104 119 135 152 170 189 209 229\r\n 4 8 13 19 26 34 43 53 64 76 89 103 118 134 151 169 188 208 228 247\r\n 7 12 18 25 33 42 52 63 75 88 102 117 133 150 168 187 207 227 246 264\r\n 11 17 24 32 41 51 62 74 87 101 116 132 149 167 186 206 226 245 263 280\r\n 16 23 31 40 50 61 73 86 100 115 131 148 166 185 205 225 244 262 279 295\r\n 22 30 39 49 60 72 85 99 114 130 147 165 184 204 224 243 261 278 294 309\r\n 29 38 48 59 71 84 98 113 129 146 164 183 203 223 242 260 277 293 308 322\r\n 37 47 58 70 83 97 112 128 145 163 182 202 222 241 259 276 292 307 321 334\r\n 46 57 69 82 96 111 127 144 162 181 201 221 240 258 275 291 306 320 333 345\r\n 56 68 81 95 110 126 143 161 180 200 220 239 257 274 290 305 319 332 344 355\r\n 67 80 94 109 125 142 160 179 199 219 238 256 273 289 304 318 331 343 354 364\r\n 79 93 108 124 141 159 178 198 218 237 255 272 288 303 317 330 342 353 363 372\r\n 92 107 123 140 158 177 197 217 236 254 271 287 302 316 329 341 352 362 371 379\r\n 106 122 139 157 176 196 216 235 253 270 286 301 315 328 340 351 361 370 378 385\r\n 121 138 156 175 195 215 234 252 269 285 300 314 327 339 350 360 369 377 384 390\r\n 137 155 174 194 214 233 251 268 284 299 313 326 338 349 359 368 376 383 389 394\r\n 154 173 193 213 232 250 267 283 298 312 325 337 348 358 367 375 382 388 393 397\r\n 172 192 212 231 249 266 282 297 311 324 336 347 357 366 374 381 387 392 396 399\r\n 191 211 230 248 265 281 296 310 323 335 346 356 365 373 380 386 391 395 398 400\r\n ];\r\n\r\nassert(isequal(not_hankel(N),mx_correct))\r\n\r\n\r\n\r\n%%\r\nN = 3;\r\n\r\nmx_correct = [...\r\n 1 3 6\r\n 2 5 8\r\n 4 7 9\r\n ];\r\n\r\nassert(isequal(not_hankel(N),mx_correct))\r\n\r\n\r\n\r\n%%\r\nrng('shuffle')\r\nN = randi(99)+5;\r\nr = repmat((0:(N-1))',1,N) + (0:(N-1));\r\np = ((.5.*r.^2 + .5.*r) + (r(1,:)+1));\r\nq = rot90(hankel(fliplr(0:N-1)),2).^2;\r\nmx_correct = p - q;\r\nassert(isequal(not_hankel(N),mx_correct))\r\n\r\n\r\n\r\n%% \r\nN = 2;\r\nmx_correct =...\r\n[...\r\n 1 3\r\n 2 4 \r\n];\r\n\r\nassert(isequal(not_hankel(N),mx_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":18354,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":22,"test_suite_updated_at":"2020-05-22T17:05:13.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2020-05-22T16:46:56.000Z","updated_at":"2026-01-20T13:24:26.000Z","published_at":"2020-05-22T16:46:56.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven a single input\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e, create a\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e x\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e matrix that counts from 1 :\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eN\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e ², (along up-right diagonals, starting with 1 in the top left corner. For example, given N=4...\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[1 3 6 10\\n2 5 9 13 \\n4 8 12 15 \\n7 11 14 16]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNotice as you move up a row and right a column (↗) the values always increase by one. The value '1' should always go in the top left corner, with '2' directly below it. From there fill in the upward-rightward diagonals with the next higher integer until the matrix is complete. Assume N will always be a positive integer greater than 1 (N \u0026gt;= 2).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2455,"title":"Diagonal of a Spiral Matrix","description":"Write a function that will return same output as diag(spiral(n)). The only exception is that spiral and diag functions are not allowed in your function. Also, loops are not allowed.","description_html":"\u003cp\u003eWrite a function that will return same output as diag(spiral(n)). The only exception is that spiral and diag functions are not allowed in your function. Also, loops are not allowed.\u003c/p\u003e","function_template":"function y=digSpi(n)\r\n\r\n\r\n\r\n\r\nend","test_suite":"s = evalc('type digSpi');\r\n\r\nif ~isempty(regexp(s,'error'))\r\n error('error using error');\r\nend\r\n\r\nif ~isempty(regexp(s,'assert'))\r\n error('error using assert');\r\nend\r\n\r\nif ~isempty(regexp(s,'diag'))\r\n error('error using diag');\r\nend\r\n\r\nif ~isempty(regexp(s,'spiral'))\r\n error('error using spiral');\r\nend\r\n\r\nif ~isempty(regexp(s,'for'))\r\n error('error using for');\r\nend\r\n\r\nif ~isempty(regexp(s,'while'))\r\n error('error using while');\r\nend\r\n\r\n%%\r\n\r\na = diag(spiral(4));\r\nb = digSpi(4);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(5));\r\nb = digSpi(5);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(6));\r\nb = digSpi(6);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(7));\r\nb = digSpi(7);\r\nassert(isequal(a,b));\r\n\r\n%%\r\n\r\na = diag(spiral(8));\r\nb = digSpi(8);\r\nassert(isequal(a,b));","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":17203,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":111,"test_suite_updated_at":"2014-07-21T18:30:07.000Z","rescore_all_solutions":false,"group_id":31,"created_at":"2014-07-20T08:15:09.000Z","updated_at":"2026-03-04T17:27:33.000Z","published_at":"2014-07-20T08:15:09.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWrite a function that will return same output as diag(spiral(n)). The only exception is that spiral and diag functions are not allowed in your function. Also, loops are not allowed.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":59242,"title":"Construct numbers from antidiagonals of stacks of binary numbers","description":"A sequence is constructed in the following way: Express the numbers 1, 2, 3, 4, 5,… in binary and stack them, right-justified. Then read the numbers in upward sloping diagonals and convert to decimal. The first four binary numbers are 11, 110, 101, 100, and their decimal equivalents are 3, 6, 5, 4. \r\n0 0 0 1\r\n0 0 1 0 \r\n0 0 1 1 \r\n0 1 0 0\r\n0 1 0 1\r\n0 1 1 0 \r\nWrite a function to compute the th term in the sequence. ","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 273px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 136.5px; transform-origin: 407px 136.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 384px 8px; transform-origin: 384px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eA sequence is constructed in the following way: Express the numbers 1, 2, 3, 4, 5,… in binary and stack them, right-justified. Then read the numbers in upward sloping diagonals and convert to decimal. The first four binary numbers are 11, 110, 101, 100, and their decimal equivalents are 3, 6, 5, 4. \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.95px 8px; transform-origin: 26.95px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 0 0 1\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 30.8px 8px; transform-origin: 30.8px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 0 1 0 \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 30.8px 8px; transform-origin: 30.8px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 0 1 1 \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.95px 8px; transform-origin: 26.95px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 1 0 0\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.95px 8px; transform-origin: 26.95px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 1 0 1\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 30.8px 8px; transform-origin: 30.8px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-family: Menlo, Monaco, Consolas, \u0026quot;Courier New\u0026quot;, monospace; \"\u003e0 1 1 0 \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 98.6583px 8px; transform-origin: 98.6583px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eWrite a function to compute the \u003c/span\u003e\u003c/span\u003e\u003cspan style=\"font-family: \u0026quot;STIXGeneral\u0026quot;, \u0026quot;STIXGeneral-webfont\u0026quot;, serif; font-style: italic; font-weight: 400; color: rgb(0, 0, 0);\"\u003en\u003c/span\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 77.0083px 8px; transform-origin: 77.0083px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eth term in the sequence. \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = slopingBinary(n)\r\n y = diag(dec2bin(1:n)');\r\nend","test_suite":"%%\r\nn = 4;\r\ny_correct = 4;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 12;\r\ny_correct = 28;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 27;\r\ny_correct = 61;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 59;\r\ny_correct = 93;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 122;\r\ny_correct = 190;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 249;\r\ny_correct = 379;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 1015;\r\ny_correct = 1529;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 2038;\r\ny_correct = 3066;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 4085;\r\ny_correct = 6143;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 8180;\r\ny_correct = 12276;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 16537;\r\ny_correct = 16539;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 485373;\r\ny_correct = 485383;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 7341901;\r\ny_correct = 7341911;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 55988359;\r\ny_correct = 55988361;\r\nassert(isequal(slopingBinary(n),y_correct))\r\n\r\n%%\r\nn = 1073741824;\r\nassert(isequal(slopingBinary(n),n))\r\n\r\n%%\r\nn = 17179869184;\r\nassert(isequal(slopingBinary(n),n))\r\n\r\n%%\r\nassert(isequal(slopingBinary(flintmax/2),flintmax/2))\r\n\r\n%%\r\nn = 899423417;\r\nyyyy_correct = 899423465;\r\ny = slopingBinary(slopingBinary(slopingBinary(slopingBinary(n))));\r\nassert(isequal(y,yyyy_correct))\r\n\r\n%%\r\nfiletext = fileread('slopingBinary.m');\r\nillegal = contains(filetext, 'assignin') || contains(filetext, 'assert') || contains(filetext,'regexp'); \r\nassert(~illegal)","published":true,"deleted":false,"likes_count":1,"comments_count":2,"created_by":46909,"edited_by":46909,"edited_at":"2023-11-28T03:00:34.000Z","deleted_by":null,"deleted_at":null,"solvers_count":5,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2023-11-28T03:00:26.000Z","updated_at":"2023-11-28T03:00:34.000Z","published_at":"2023-11-28T03:00:34.000Z","restored_at":null,"restored_by":null,"spam":null,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eA sequence is constructed in the following way: Express the numbers 1, 2, 3, 4, 5,… in binary and stack them, right-justified. Then read the numbers in upward sloping diagonals and convert to decimal. The first four binary numbers are 11, 110, 101, 100, and their decimal equivalents are 3, 6, 5, 4. \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 0 0 1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 0 1 0 \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 0 1 1 \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 1 0 0\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 1 0 1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:rFonts w:cs=\\\"monospace\\\"/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e0 1 1 0 \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWrite a function to compute the \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:customXml w:element=\\\"equation\\\"\u003e\u003cw:customXmlPr\u003e\u003cw:attr w:name=\\\"displayStyle\\\" w:val=\\\"false\\\"/\u003e\u003cw:attr w:name=\\\"altTextString\\\" w:val=\\\"n\\\"/\u003e\u003c/w:customXmlPr\u003e\u003cw:r\u003e\u003cw:t\u003en\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:customXml\u003e\u003cw:r\u003e\u003cw:t\u003eth term in the sequence. \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":2585,"title":"How to reverse spdiags?","description":"The spdiags function extracts all nonzero diagonals from the m-by-n matrix A.\r\n\r\nSo if A=[1 2 3;4 5 6;7 8 9],\r\n\r\nspdiags(A)=[7 4 1 0 0;0 8 5 2 0;0 0 9 6 3].\r\n\r\nBut if I give you spdiags(A), can you give me A ?","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.44px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: none solid rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 213px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 332px 106.5px; transform-origin: 332px 106.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003eThe spdiags function extracts all nonzero diagonals from the m-by-n matrix A.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003eSo if\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgb(247, 247, 247); block-size: 20px; border-bottom-left-radius: 4px; border-bottom-right-radius: 4px; border-top-left-radius: 4px; border-top-right-radius: 4px; margin-block-end: 10px; margin-block-start: 10px; margin-bottom: 10px; margin-inline-end: 3px; margin-inline-start: 3px; margin-left: 3px; margin-right: 3px; margin-top: 10px; perspective-origin: 329px 10px; transform-origin: 329px 10px; margin-left: 3px; margin-top: 10px; margin-bottom: 10px; margin-right: 3px; \"\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e A = [1 2 3;4 5 6;7 8 9]\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 10px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 10px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 10px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003ethen\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgb(247, 247, 247); block-size: 60px; border-bottom-left-radius: 4px; border-bottom-right-radius: 4px; border-top-left-radius: 4px; border-top-right-radius: 4px; margin-block-end: 10px; margin-block-start: 10px; margin-bottom: 10px; margin-inline-end: 3px; margin-inline-start: 3px; margin-left: 3px; margin-right: 3px; margin-top: 10px; perspective-origin: 329px 30px; transform-origin: 329px 30px; margin-left: 3px; margin-top: 10px; margin-bottom: 10px; margin-right: 3px; \"\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 329px 10px; transform-origin: 329px 10px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e spdiags(A) = [7 4 1 0 0;\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 329px 10px; transform-origin: 329px 10px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e 0 8 5 2 0;\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 329px 10px; transform-origin: 329px 10px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 0px 0px; tab-size: 4; transform-origin: 0px 0px; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e 0 0 9 6 3]\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 10px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 10px; perspective-origin: 309px 10.5px; text-align: left; transform-origin: 309px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 10px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; \"\u003e\u003cspan style=\"\"\u003eBut if I give you spdiags(A), can you give me A ?\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = inv_spdiags(x)\r\n y = x;\r\nend","test_suite":"%%\r\nx = spdiags([1 2 3;4 5 6;7 8 9]);\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\nb = spdiags(eye(10));\r\nassert(isequal(spdiags(inv_spdiags(b)),b))\r\n%%\r\nx = spdiags([1 2 3;4 5 6]);\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\ny = spdiags(magic(9));\r\nassert(isequal(spdiags(inv_spdiags(y)),y))\r\n%%\r\nx = spdiags(magic(5));\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\nz = spdiags(ones(10));\r\nassert(isequal(spdiags(inv_spdiags(z)),z))\r\n%%\r\nx = spdiags(randi(10,5));\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\nx = spdiags(randi(5,[3 2]));\r\nassert(isequal(spdiags(inv_spdiags(x)),x))\r\n%%\r\na = spdiags(zeros(5));\r\nassert(isequal(spdiags(inv_spdiags(a)),a))","published":true,"deleted":false,"likes_count":2,"comments_count":1,"created_by":5390,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":43,"test_suite_updated_at":"2014-09-14T14:43:49.000Z","rescore_all_solutions":false,"group_id":39,"created_at":"2014-09-14T14:39:28.000Z","updated_at":"2026-02-15T11:51:56.000Z","published_at":"2014-09-14T14:41:28.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThe spdiags function extracts all nonzero diagonals from the m-by-n matrix A.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eSo if\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ A = [1 2 3;4 5 6;7 8 9]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ethen\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ spdiags(A) = [7 4 1 0 0;\\n 0 8 5 2 0;\\n 0 0 9 6 3]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eBut if I give you spdiags(A), can you give me A ?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"}],"term":"tag:\"diag\"","current_player_id":null,"fields":[{"name":"page","type":"integer","callback":null,"default":1,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":null,"prepend":true},{"name":"per_page","type":"integer","callback":null,"default":50,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":null,"prepend":true},{"name":"sort","type":"string","callback":null,"default":null,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":null,"prepend":true},{"name":"body","type":"text","callback":null,"default":"*:*","directive":null,"facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":false},{"name":"group","type":"string","callback":null,"default":null,"directive":"group","facet":true,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"difficulty_rating_bin","type":"string","callback":null,"default":null,"directive":"difficulty_rating_bin","facet":true,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"id","type":"integer","callback":null,"default":null,"directive":"id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"tag","type":"string","callback":null,"default":null,"directive":"tag","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"product","type":"string","callback":null,"default":null,"directive":"product","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"created_at","type":"timeframe","callback":{},"default":null,"directive":"created_at","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"profile_id","type":"integer","callback":null,"default":null,"directive":"author_id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"created_by","type":"string","callback":null,"default":null,"directive":"author","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"player_id","type":"integer","callback":null,"default":null,"directive":"solver_id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"player","type":"string","callback":null,"default":null,"directive":"solver","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"solvers_count","type":"integer","callback":null,"default":null,"directive":"solvers_count","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"comments_count","type":"integer","callback":null,"default":null,"directive":"comments_count","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"likes_count","type":"integer","callback":null,"default":null,"directive":"likes_count","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"leader_id","type":"integer","callback":null,"default":null,"directive":"leader_id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"leading_solution","type":"integer","callback":null,"default":null,"directive":"leading_solution","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true}],"filters":[{"name":"asset_type","type":"string","callback":null,"default":null,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":"\"cody:problem\"","prepend":true},{"name":"profile_id","type":"integer","callback":{},"default":null,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":"author_id","static":null,"prepend":true}],"query":{"params":{"per_page":50,"term":"tag:\"diag\"","current_player":null,"sort":"map(difficulty_value,0,0,999) 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