Peli

input/code.cpp: In function 'int main()':
input/code.cpp:26:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 if(bag.size() == k){
                    ~~~~~~~~~~~^~~~

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

#define fr(x) for(ll i = 0; i < x; i++)

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    ll n, k, ans;
    string s;

    unordered_set<char> bag;

    cin >> n >> k;
    cin >> s;

    if(k > 2){
        ans = 0;
        for (auto it = s.begin(); it != s.end(); it++)
        {
            if(bag.count(*it))
            {
                if(bag.size() == k){
                    ++ans;
                    bag.clear();
                }
            }
            else{
                bag.insert(*it);
            }
        }
        cout << ans << endl;
    }
    else{
        cout << 0 << endl;
    }
    
}

Test 1

Group: 1, 2, 3

Verdict: WRONG ANSWER

Test 2

Group: 2, 3

Verdict: WRONG ANSWER

Test 3

Group: 3

Verdict: WRONG ANSWER

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED