func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 100005;   int n, S = 0;   char x[2], s[MAXN];   int viv[MAXN];   bool use[MAXN];   int cqf() {     int l = -1, r = -1;     int ans = MAXN, sum = 0;     while (true) {       while (r <= n && sum < S) {         r++;         if (!viv[s[r]] && use[s[r]]) sum++;         viv[s[r]]++;       }       if (sum < S) break;       ans = min(ans, r - l + 1);       if (viv[s[l]] == 1 && use[s[l]]) sum--;       viv[s[l]]--;       l++;     }     return ans;   }   int main() {     memset(viv, 0, sizeof(viv));     memset(use, 0, sizeof(use));     scanf( %d , &n);     gets(x);     gets(s);     for (int i = 0; i < n; i++) {       if (use[s[i]] == false) S++;       use[s[i]] = true;     }     printf( %d n , cqf());     return 0;   }   