func_code_string: #include <bits/stdc++.h>   using namespace std;   bool nextper(int num[], int n) {     int i;     for (i = n - 1; i > 0; i--) {       if (num[i] > num[i - 1]) {         for (int j = n - 1; j >= i; j--) {           if (num[j] > num[i - 1]) {             int t = num[j];             num[j] = num[i - 1];             num[i - 1] = t;             for (int m = i, k = n - 1; m < k; m++, k--) {               t = num[m];               num[m] = num[k];               num[k] = t;             }             break;           }         }         break;       }     }     if (i > 0) {       return true;     } else       return false;   }   int order[8] = {0, 1, 2, 3, 4, 5, 6, 7};   char s[8][9];   int main() {     int n, k, i, j, min, max, num, ans = 2147483647;     scanf( %d %d , &n, &k);     for (i = 0; i < n; i++) scanf( %s , s[i]);     do {       min = 2147483647;       max = 0;       for (i = 0; i < n; i++) {         num = 0;         for (j = 0; j < k; j++) num = num * 10 + (s[i][order[j]] -  0 );         if (min > num) min = num;         if (max < num) max = num;       }       if (max - min < ans) ans = max - min;     } while (nextper(order, k));     printf( %d n , ans);   }   