TAChi-T005: Frequency Count

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

map<int, int> mp, fq;

int main(){

    int Q;
    scanf("%d", &Q);
    while(Q--){
        int cmd, x;
        scanf("%d%d", &cmd, &x);
        if(cmd == 1){
            int f = mp[x]++;
            if(fq[f] > 0){
                --fq[f];
            }
            ++fq[f + 1];
        } else if(cmd == 2){
            if(mp[x] == 0){
                continue;
            }
            int f = mp[x]--;
            --fq[f];
            ++fq[f - 1];
        } else if(cmd == 3){
            if(fq[x] == 0){
                cout << "0\n";
            } else {
                cout << "1\n";
            }
        }
    }

    return 0;
}