In an alternating permutation of numbers 1 to n, the numbers are arranged so that they alternately increase and decrease. For example, there are five alternating permutations of the numbers 1, 2, 3, and 4:
1 3 2 4
1 4 2 3
2 3 1 4
2 4 1 3
3 4 1 2
Write a function to count the alternating permutations for a set of n numbers.
Solution Stats
Problem Comments
3 Comments
Solution Comments
Show comments
Loading...
Problem Recent Solvers14
Suggested Problems
-
14386 Solvers
-
323 Solvers
-
297 Solvers
-
Flip the main diagonal of a matrix
927 Solvers
-
Create a matrix with difference of each row of input matrix
76 Solvers
More from this Author329
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
The test case result for n=5 seems a tad high.
Tim, that last case is altperm(altperm(5)). I did that to discourage lookup solutions.
Oops--my mistake.