Package g0501_0600.s0526_beautiful_arrangement

Class Solution

java.lang.Object
g0501_0600.s0526_beautiful_arrangement.Solution
public class Solution extends java.lang.Object
526 - Beautiful Arrangement.

Medium

Suppose you have n integers labeled 1 through n. A permutation of those n integers perm ( 1-indexed ) is considered a beautiful arrangement if for every i (1 <= i <= n), either of the following is true:

  • perm[i] is divisible by i.
  • i is divisible by perm[i].

Given an integer n, return the number of the beautiful arrangements that you can construct.

Example 1:

Input: n = 2

Output: 2

Explanation:

The first beautiful arrangement is [1,2]:

  • perm[1] = 1 is divisible by i = 1

  • perm[2] = 2 is divisible by i = 2

The second beautiful arrangement is [2,1]:

  • perm[1] = 2 is divisible by i = 1

  • i = 2 is divisible by perm[2] = 1

Example 2:

Input: n = 1

Output: 1

Constraints:

  • 1 <= n <= 15

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    countArrangement(int n)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • countArrangement

      public int countArrangement(int n)