Dùng chặt nhị phân code c++ giúp mình với ạ !!

#include <bits/stdc++.h>
using namespace std;
const int N=1e6+5;
int a[N],n;
int bs(int x) {
	int ans=-1,l=1,r=n;
	while(l<=r) {
		int m=(l+r)/2;
		if(a[m]>=x){
			ans=m;
			r=m-1;
		}
		else l=m+1;
	}
	return ans;
}
int binaryS(int x){
	int ans=-1,l=1,r=n;
	while(l<=r){
		int m=(l+r)/2;
		if(a[m]<=x){
			ans=m;
			l=m+1;
		}
		else r=m-1;
	}
	return ans;
}
signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin>>n;
	for(int i=1; i<=n; i++)cin>>a[i];
	sort(a+1,a+1+n);
	int q;
	cin>>q;
	while(q--) {
		int l,r;
		cin>>l>>r;
		int bs1=bs(l),bs2=binaryS(r);
		if(bs1!=-1&&bs2!=-1)
			cout<<bs2-bs1+1<<"\n";
		else cout<<0<<"\n";
	}
}

#danglam228

#include <bits/stdc++.h>
using namespace std;
int n;
int tt1(vector<int>& a, int g) {
    int l = 0, r = a.size();
    while (l < r) {
        int m = l + (r - l) / 2;
        if (a[m] < g) {
            l = m + 1;
        } else {
            r = m;
        }
    }
    return l;
}
int tt2(vector<int>& a, int g) {
    int l = 0, r = a.size();
    while (l < r) {
        int m = l + (r - l) / 2;
        if (a[m] <= g) {
            l = m + 1;
        } else {
            r = m;
        }
    }
    return l;
}
int main() {
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    int q;
    cin >> q;
    vector<pair<int, int>> f(q);
    for (int i = 0; i < q; ++i) {
        cin >> f[i].first >> f[i].second;
    }
    sort(a.begin(), a.end());
    for (int i = 0; i < q; ++i) {
        int l = f[i].first;
        int r = f[i].second;
        int ll = tt1(a, l);
        int rr = tt2(a, r);
        cout << rr - ll << endl;
    }
    return 0;
}