func_code_string: #include <bits/stdc++.h>   using namespace std;   int fromStrtoInt(string s, string c) {     int x = 0;     for (int i = 0; i < c.size(); i++) {       x *= 10;       x += s[c[i] -  0 ] -  0 ;     }     return x;   }   int main() {     int n, k;     cin >> n >> k;     string s, arr[n];     for (int i = 0; i < n; i++) cin >> arr[i];     for (int i = 0; i < k; i++) s += i +  0 ;     int a[n];     int ans = 1e9;     do {       for (int i = 0; i < n; i++) a[i] = fromStrtoInt(arr[i], s);       sort(a, a + n);       ans = min(ans, a[n - 1] - a[0]);     } while (next_permutation(s.begin(), s.end()));     cout << ans;     return 0;   }   