leetcode

0 class Solution {

1 static const int MOD = 1e9 + 7;

2 long dp[101][101] = {1, 0};

3

4 public:

5 int numMusicPlaylists(int n, int goal, int k) {

6 for (int i = 1; i <= goal; i++) {

7 for (int j = 1; j <= n; j++) {

8 dp[i][j] = (dp[i - 1][j - 1] * (n - (j - 1))) % MOD;

9 if (j > k) {

10 dp[i][j] = (dp[i][j] + (dp[i - 1][j] * (j - k)) % MOD) % MOD;

11 }

12 }

13 }

14 return (int)dp[goal][n];

15 }

16 };