func_code_string: #include <bits/stdc++.h>   using namespace std;   char str[25][25];   int cost[25][25];   const int maxc = 1 << 20;   int dp[maxc];   int main() {     int n, m;     scanf( %d%d , &n, &m);     for (int i = 0; i < n; i++) scanf( %s , str + i);     for (int i = 0; i < n; i++) {       for (int j = 0; j < m; j++) scanf( %d , &cost[i][j]);     }     int total = (1 << n) - 1;     memset(dp, -1, sizeof(dp));     dp[0] = 0;     for (int i = 0; i < total; i++) {       if (dp[i] == -1) continue;       int j = 0;       while (((i >> j) & 1) == 1) j++;       for (int k = 0; k < m; k++) {         int cnt = 0, sumc = 0, maxc = 0, tmp = 0;         for (int z = 0; z < n; z++) {           if (str[z][k] == str[j][k]) {             cnt++;             sumc += cost[z][k];             maxc = max(maxc, cost[z][k]);             tmp |= (1 << z);           }         }         if (cnt == 1) {           if (dp[i | (1 << j)] == -1)             dp[i | (1 << j)] = dp[i];           else             dp[i | (1 << j)] = min(dp[i | (1 << j)], dp[i]);         } else {           if (dp[i | (1 << j)] == -1)             dp[i | (1 << j)] = dp[i] + cost[j][k];           else             dp[i | (1 << j)] = min(dp[i | (1 << j)], dp[i] + cost[j][k]);           if (dp[i | tmp] == -1)             dp[i | tmp] = dp[i] + sumc - maxc;           else             dp[i | tmp] = min(dp[i | tmp], dp[i] + sumc - maxc);         }       }     }     printf( %d n , dp[total]);     return 0;   }   