func_code_string: #include <bits/stdc++.h>   using namespace std;   const int OO = 0x3f3f3f3f, N = 1e5 + 5, mod = 1e9 + 9;   int n, k, indx[10], ans = OO;   char arr[10][10];   int num(int r) {     int ret = 0;     for (int i = 0; i < k; ++i) {       ret = ret * 10 + (arr[r][indx[i]] -  0 );     }     return ret;   }   int main() {     cin >> n >> k;     for (int i = 0; i < k; ++i) indx[i] = i;     for (int i = 0; i < n; ++i) scanf( %s , arr[i]);     do {       int mn = OO, mx = 0;       for (int i = 0; i < n; ++i) {         mn = min(mn, num(i));         mx = max(mx, num(i));       }       ans = min(ans, mx - mn);     } while (next_permutation(indx, indx + k));     cout << ans;     return 0;   }   