I - Binary search - 1

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

signed main()
{
    int n , q , x;
    cin >> n >> q;
    vector<int> a(n);
    for(int i = 0; i < n; i++)
        cin >> a[i];

    sort(a.begin() , a.end()); // O(n logn)

    while(q--){
        cin >> x;
        auto e = equal_range(a.begin() , a.end() , x);
        cout << e.second - e.first << endl;
/*
        int l = lower_bound(a.begin() , a.end() , x) - a.begin();
        int r = upper_bound(a.begin() , a.end() , x) - a.begin();
        cout << (r - l) << endl;*/
    }
}