62 total contributions since 2012

Professional Interests: writing, user experience

Solved

Which doors are open?

There are n doors in an alley. Initially they are all shut. You have been tasked to go down the alley n times, and open/shut the...

meer dan 7 jaar ago

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QWERTY coordinates

Given a lowercase letter or a digit as input, return the row where that letter appears on a <http://en.wikipedia.org/wiki/Keyboa...

meer dan 7 jaar ago

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Summing Digits within Text

Given a string with text and digits, add all the numbers together. Examples: Input str = '4 and 20 blackbirds baked in a...

meer dan 7 jaar ago

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Reverse Run-Length Encoder

Given a "counting sequence" vector x, construct the original sequence y. A counting sequence is formed by "counting" the entrie...

bijna 8 jaar ago

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Trimming Spaces

Given a string, remove all leading and trailing spaces (where space is defined as ASCII 32). Input a = ' singular value deco...

bijna 8 jaar ago

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Pattern matching

Given a matrix, m-by-n, find all the rows that have the same "increase, decrease, or stay same" pattern going across the columns...

bijna 8 jaar ago

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Balanced number

Given a positive integer find whether it is a balanced number. For a balanced number the sum of first half of digits is equal to...

bijna 8 jaar ago

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Return a list sorted by number of occurrences

Given a vector x, return a vector y of the unique values in x sorted by the number of occurrences in x. Ties are resolved by a ...

bijna 8 jaar ago

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De-dupe

Remove all the redundant elements in a vector, but keep the first occurrence of each value in its original location. So if a =...

bijna 8 jaar ago

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Making change

Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = ...

bijna 8 jaar ago

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Elapsed Time

Given two date strings d1 and d2 of the form yyyy/mm/dd HH:MM:SS (assume hours HH is in 24 hour mode), determine how much time, ...

bijna 8 jaar ago

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Replace NaNs with the number that appears to its left in the row.

Replace NaNs with the number that appears to its left in the row. If there are more than one consecutive NaNs, they should all ...

bijna 8 jaar ago

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Stuff the Board

You have a stack of tiles to put onto an array-like playing board. Each tile has a number (always an integer), and the board var...

bijna 8 jaar ago

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Scoring for oriented dominoes

Given a list of ordered pairs, and the order they should be placed in a line, find the sum of the absolute values of the differe...

bijna 8 jaar ago

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Counting Money

Add the numbers given in the cell array of strings. The strings represent amounts of money using this notation: $99,999.99. E...

bijna 8 jaar ago

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Remove all the consonants

Remove all the consonants in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill'; Output s2 is 'a ...

bijna 8 jaar ago

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Find the longest sequence of 1's in a binary sequence.

Given a string such as s = '011110010000000100010111' find the length of the longest string of consecutive 1's. In this examp...

bijna 8 jaar ago

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The Hitchhiker's Guide to MATLAB

Output logical "true" if the input is the answer to life, the universe and everything. Otherwise, output logical "false".

bijna 8 jaar ago

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Pangrams!

A pangram, or holoalphabetic sentence, is a sentence using every letter of the alphabet at least once. Example: Input s ...

bijna 8 jaar ago

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Find the alphabetic word product

If the input string s is a word like 'hello', then the output word product p is a number based on the correspondence a=1, b=2, ....

bijna 8 jaar ago

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Quote Doubler

Given a string s1, find all occurrences of the single quote character and replace them with two occurrences of the single quote ...

bijna 8 jaar ago

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radius of a spherical planet

you just measured its surface area, that is the input.

bijna 8 jaar ago

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Distance walked 1D

Suppose you go from position 7 to 10 to 6 to 4. Then you have walked 9 units of distance, since 7 to 10 is 3 units, 10 to 6 is 4...

bijna 8 jaar ago

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Sum all integers from 1 to 2^n

Given the number x, y must be the summation of all integers from 1 to 2^x. For instance if x=2 then y must be 1+2+3+4=10.

bijna 8 jaar ago

Solved

The Goldbach Conjecture, Part 2

The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

bijna 8 jaar ago

Problem

Penny Flipping: Reverse subsets of a sequence of coins until you recover the original configuration

The original Penny Flipping Problem (PF-1) starts with a stack of N pennies arranged with all the coins heads up. The first oper...

bijna 8 jaar ago | 1

Solved

Penny Flipping: Reverse subsets of a sequence of coins until you recover the original configuration

The original Penny Flipping Problem (PF-1) starts with a stack of N pennies arranged with all the coins heads up. The first oper...

bijna 8 jaar ago

Solved

Bullseye Matrix

Given n (always odd), return output a that has concentric rings of the numbers 1 through (n+1)/2 around the center point. Exampl...

bijna 8 jaar ago

Solved

Pascal's Triangle

Given an integer n >= 0, generate the length n+1 row vector representing the n-th row of <http://en.wikipedia.org/wiki/Pascals_t...

bijna 8 jaar ago