func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, k;     cin >> n >> k;     cin.get();     vector<string> v(n);     for (int i = 0; i < n; i++) getline(cin, v[i]);     vector<int> p(k);     for (int i = 0; i < k; i++) p[i] = i;     int minDiff = INT_MAX;     do {       int minNum, maxNum;       minNum = INT_MAX;       maxNum = INT_MIN;       for (int i = 0; i < n; i++) {         int num = 0;         for (int j = 0; j < k; j++) num = num * 10 + v[i][p[j]] -  0 ;         if (num < minNum) minNum = num;         if (num > maxNum) maxNum = num;       }       minDiff = min(minDiff, maxNum - minNum);     } while (next_permutation(p.begin(), p.end()));     cout << minDiff;     return 0;   }   