Peli

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

int n,k;
string d;
set<char> s;

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

    cin>>n>>k;
    cin>>d;
    if(k!=3){
        cout<<"0\n";
        return 0;
    }
    int p=0;
    for(int i=0;i<n;i++){
        if(s.count(d[i])==0)s.insert(d[i]);
        if(s.count('A')==1&&s.count('B')==1&&s.count('C')==1){
            p++;
            s.erase('A');
            s.erase('B');
            s.erase('C');
        }
    }
    cout<<p<<"\n";
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

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