Problem 46037. Count alternating permutations

Created by ChrisR

Solve Later

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.
Suggestion: You might also try Cody Problem 46034.

Solve

Solution Stats

17 Solutions
10 Solvers

Last Solution submitted on Aug 26, 2024

Last 200 Solutions

Problem Comments

3 Comments

3 Comments

Tim on 10 Jul 2020

The test case result for n=5 seems a tad high.

ChrisR on 10 Jul 2020

Tim, that last case is altperm(altperm(5)). I did that to discourage lookup solutions.

Tim on 10 Jul 2020

Oops--my mistake.

Solution Comments

Show comments

Problem Recent Solvers10

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 46037. Count alternating permutations

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers10

Suggested Problems

More from this Author321

Problem Tags

Community Treasure Hunt

Problem 46037. Count alternating permutations

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers10

Suggested Problems

More from this Author321

Problem Tags

Community Treasure Hunt

Players