бинпоиск для кирюши

#include <iostream>
#include <string>
#include <sstream>
#include <cmath>
#include <algorithm>
#include <memory.h>
#include <stdio.h>
#include <vector>
#include <stack>
#include <deque>
#include <queue>
#include <vector>
#include <set>
using namespace std;

vector <int> vc;

int left_bin(int l, int r, int key)
{
    int m;
    while (r - l > 1)
    {
        m = (r + l) / 2;
        if (vc[m] > key)
        {
            r = m;
        }
        else
        {
            l = m;
        }
    }
    /*if (vc[l] > key && l + 1 < vc.size())
    {
        return  l + 1;
    }*/
    if (vc[vc.size() - 1] < key || vc[r] == key)
    {
        return r;
    }
    if (vc[l] <= key)
    {
        return l;
    }

    return -1;
}

int right_bin(int l, int r, int key)
{
    int m;
    while (r - l > 1)
    {
        m = (r + l) / 2;
        if (vc[m] >= key)
        {
            r = m;
        }
        else
        {
            l = m;
        }
    }
    /*if (vc[r] > key && r + 1 < vc.size())
    {
        return  r + 1;
    }*/
    if (vc[0] > key || vc[l] == key)
    {
        return l;
    }
    if (vc[r] >= key)
    {
        return r;
    }
    return -1;
}


int main() {
    int n, q;
    cin >> n;

    for (int i = 0; i < n; i++)
    {
        cin >> q;
        vc.push_back(q);
    }

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

    /*for (int i = 0; i < n; i++)
    {
        cout << vc[i] << " ";
    }
    cout << endl;*/

    int k, l, r, a1, a2;
    cin >> k;

    for (int i = 0; i < k; i++)
    {
        cin >> l >> r;
        a1 = left_bin(0, n - 1, r);
        if (a1 == -1)
        {
            cout << 0 << " ";
        }
        else
        {
            a2 = right_bin(0, n - 1, l);
            if (a2 == -1)
            {
                cout << 0 << " ";
            }
            else
            {
                cout << a1 - a2 + 1 << " ";
            }
        }
    }
    system("pause");
    return 0;

}