3970. Mutants

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define mp make_pair
#define pb push_back

signed main() {
    ios::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);

    int n;
    cin >> n;

    vector<int> v(n);

    for(int i=0;i<n;i++)
    {
        cin >> v[i];
    }

    int t;
    cin >> t;

    sort(v.begin(),v.end());

    int left,right;
    int L,R;
    int mid;

    int a;

    while(t--)
    {
        cin >> a;
        if(n == 0)
        {
            cout << "0\n";
            continue;
        }
        L = 0,R = n-1;
        while(R-L>1)
        {
            mid = (R+L)/2;
            if(v[mid] > a)
                R = mid;
            else
                L = mid;
        }

        if(v[L] != a && v[R] != a)
        {
            cout << "0\n";
            continue;
        }

        right = (v[R] == a ? R : L);

        L = 0,R = n-1;
        while(R-L>1)
        {
            mid = (R+L)/2;
            if(v[mid] < a)
                L = mid;
            else
                R = mid;
        }
        left = (v[L] == a ? L : R);

        if(right < left)
            swap(right,left);

        cout << right - left + 1 << "\n";
    }

    return 0;
}