CUBE-T188: Lazy

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

typedef map<int, vector<int>>::iterator mvit;
typedef vector<int>::iterator vit;

map<int, vector<int>> mp;

int main(){

    int nNumber, Q;
    scanf("%d%d", &nNumber, &Q);
    for(int i = 1; i <= nNumber; ++i){
        int x;
        scanf("%d", &x);
        mvit itr = mp.find(x);
        if(itr == mp.end()){
            mp.emplace(x, vector<int>(1, i));
        } else {
            (itr -> second).push_back(i);
        }
    }

    for(int q = 1; q <= Q; ++q){
        int l, r, x;
        scanf("%d%d%d", &l, &r, &x);
        mvit itr = mp.find(x);
        if(itr == mp.end()){
            cout << "0\n";
        } else {
            vit lwb = lower_bound((itr -> second).begin(), (itr -> second).end(), l);
            vit upb = upper_bound((itr -> second).begin(), (itr -> second).end(), r);
            cout << upb - lwb << '\n';
        }
    }

    return 0;
}