Java | Leetcode Java题解之第526题优美的排列
题目：
题解：
class Solution {
public int countArrangement(int n) {
int[] f = new int[1 << n];
f[0] = 1;
for (int mask = 1; mask < (1 << n); mask++) {
int num = Integer.bitCount(mask);
for (int i = 0; i < n; i++) {
if ((mask & (1 << i)) != 0 && ((num % (i + 1)) == 0 || (i + 1) % num == 0)) {
f[mask] += f[mask ^ (1 << i)];
}
}
}
return f[(1 << n) - 1];
}
}