Envío 2361

Código

#include<bits/stdc++.h>
using namespace std;

int main(){
    string see;
    cin >> see;
    int k;
    cin >> k;
    map<char,int> counter;
    int ans = 100000000;
    int i = 0, j = -1;
    while(j < (int)see.size()){
        while(counter.size() == k){
            --counter[see[i]];
            if(counter[see[i]] == 0)
                counter.erase(see[i]);
            ++i;
        }
        while(j < (int)see.size() && counter.size() != k){
            ++j;
            ++counter[see[j]];
        }
        while(counter.size() == k){
            if(counter[see[i]] != 1) {
                --counter[see[i]];
                ++i;
            }
            else break;
        }
        if(j != see.size())
            ans = min(ans,j-i+1);
    }
    if(ans == 100000000) ans = -1;
    printf("%d\n",ans);
    return 0;
}