func_code_string: #include <bits/stdc++.h>   using namespace std;   char st[100000];   int n, t, a[26], minn, maxx;   int main() {     scanf( %d%d , &n, &t);     scanf( %s , st);     minn = 25;     maxx = 0;     for (int i = 0; i < n; i++) {       if (st[i] - 97 < minn) minn = st[i] - 97;       if (st[i] - 97 > maxx) maxx = st[i] - 97;       a[st[i] - 97] = 1;     }     if (t > n) {       printf( %s , st);       for (int i = n + 1; i <= t; i++) printf( %c , minn + 97);     } else {       int wei = t - 1;       while (st[wei] - 97 == maxx) {         st[wei] = minn + 97;         wei--;       }       st[wei]++;       while (a[st[wei] - 97] == 0) st[wei]++;       for (int i = 0; i < t; i++) printf( %c , st[i]);       printf(  n );     }     return 0;   }   