g0501_0600.s0526_beautiful_arrangement

Class Solution

java.lang.Object

g0501_0600.s0526_beautiful_arrangement.Solution

public class Solution
extends 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 and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	countArrangement(int n)

Methods inherited from class java.lang.Object

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

Constructor Detail

Solution

public Solution()

Method Detail

countArrangement

public int countArrangement(int n)