SMMR-Chi-005: Frequency Count

#include <bits/stdc++.h>

using namespace std;

unordered_map <int, int> val, freq;

int main(){

    int Q;
    scanf("%d", &Q);

    for(int q=1;q<=Q;q++){
        int opr, x;
        scanf("%d %d", &opr, &x);
        if(opr == 3){
            if(freq[x] > 0) printf("1\n");
            else printf("0\n");
        }
        else if(opr == 1){
            if(freq[ val[x] ] > 0) freq[ val[x] ] --;
            val[x] ++;
            freq[ val[x] ] ++;
        }
        else{
            if(val[x] == 0) continue;
            if(freq[ val[x] ] > 0) freq[ val[x] ] --;
            val[x] --;
            freq[ val[x] ] ++;
        }
    }

    return 0;
}