func_code_string: #include <bits/stdc++.h>   using namespace std;   double C[55][55], dp[55][55][55];   int a[55], n, m;   double dfs(int i, int j, int k) {     if (dp[i][j][k] != -1.0) return dp[i][j][k];     double ret = 0;     for (int c = 0; c <= i; c++) {       int maxq = max(k, int((c + a[j] - 1) / a[j]));       ret += dfs(i - c, j - 1, maxq) * C[i][c] * pow(j - 1, i - c) / pow(j, i);     }     return dp[i][j][k] = ret;   }   int main() {     int i, j, k, maxq;     memset(C, 0, sizeof(C));     C[0][0] = 1;     for (i = 1; i <= 50; i++) {       C[i][0] = 1;       for (j = 1; j <= i; j++) {         C[i][j] = C[i - 1][j - 1] + C[i - 1][j];       }     }     while (cin >> n >> m) {       for (i = 1; i <= m; i++) scanf( %d , &a[i]);       for (i = 0; i <= 50; i++)         for (j = 0; j <= 50; j++)           for (k = 0; k <= 50; k++) dp[i][j][k] = -1.0;       for (i = 0; i <= n; i++) {         dp[0][0][i] = i;         for (k = 0; k <= 50; k++) dp[i][0][k] = 0;       }       printf( %.12f n , dfs(n, m, 0));     }   }   