Leetcode 526 Beautiful Arrangement

Leetcde 526 Beautiful Arrangement

C++版。

解题思想：

回溯。

AC代码如下，仅供参考。

class Solution {public:int countArrangement(int N) {vector<int>states(N+1, 0);int count = 0;arrange(states, count, 1, N);return count;}void arrange(vector<int>& states, int& count, int i, int N) {if (i > N) {count++;return;}for (int q = 1; q <= N; q++) {if (!states.at(q)&&(q % i == 0 || i % q == 0)) {states.at(q) = 1;arrange(states, count, i+1, N);states.at(q) = 0;}}}};