func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     vector<int> a;     string s;     int n, k, b[100][100], t, res = 99999999999, min, max;     cin >> n >> k;     getline(cin, s);     for (int i = 0; i < n; i++) {       getline(cin, s);       for (int j = 0; j < s.length(); j++) b[i][j] = (int)(s[j] -  0 );     }     for (int i = 0; i < k; i++) a.push_back(i);     do {       min = 99999999999;       max = 0;       for (int i = 0; i < n; i++) {         t = 0;         for (int j = 0; j < k; j++) t = t * 10LL + b[i][a[j]];         if (t > max) max = t;         if (t < min) min = t;       }       if (max - min < res) res = max - min;     } while (next_permutation(a.begin(), a.end()));     cout << res;     return 0;   }   