Package g0501_0600.s0526_beautiful_arrangement

Class Solution

java.lang.Object

g0501_0600.s0526_beautiful_arrangement.Solution

public class Solution
extends Object

526 - Beautiful Arrangement.<p>Medium</p> <p>Suppose you have <code>n</code> integers labeled <code>1</code> through <code>n</code>. A permutation of those <code>n</code> integers <code>perm</code> ( <strong>1-indexed</strong> ) is considered a <strong>beautiful arrangement</strong> if for every <code>i</code> (<code>1 <= i <= n</code>), <strong>either</strong> of the following is true:</p> <ul> <li><code>perm[i]</code> is divisible by <code>i</code>.</li> <li><code>i</code> is divisible by <code>perm[i]</code>.</li> </ul> <p>Given an integer <code>n</code>, return <em>the <strong>number</strong> of the <strong>beautiful arrangements</strong> that you can construct</em>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> n = 2</p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <p>The first beautiful arrangement is [1,2]:</p> <ul> <li> <p>perm[1] = 1 is divisible by i = 1</p> </li> <li> <p>perm[2] = 2 is divisible by i = 2</p> </li> </ul> <p>The second beautiful arrangement is [2,1]:</p> <ul> <li> <p>perm[1] = 2 is divisible by i = 1</p> </li> <li> <p>i = 2 is divisible by perm[2] = 1</p> </li> </ul> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> n = 1</p> <p><strong>Output:</strong> 1</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= n <= 15</code></li> </ul>

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)