Binary search c++

void BinarnyInt2(int arr[], int z, int n) {
    auto start = chrono::high_resolution_clock::now();
    int l = 0;
    int r = n - 1;
    int search = -1;
    while (l <= r)
    {
        int m = (l + r) / 2;
        if (arr[m] == z){
            search = 0;
            cout  << m << endl;
        }
        if (arr[m] < z)
            l = m + 1;
        else
            r = m - 1;
    }
    auto finish = chrono::high_resolution_clock::now();
    chrono::duration<double> elapsed = (finish - start) * 1000;
    cout << "Время: " << elapsed.count() << " ms" << endl;
    if (search == -1) {
        cout << "Елемент не найден" << endl;
    }
}

#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <ctime>
 
using namespace std;
 
void LinearSearch(int* A, int N, int X)
{
    int index = -1;
    for (int i = 0; i < N; i++) {
        if (A[i] == X) {
            index = i;
            break;
        }
    }
    
    if (index == -1) {
        cout << "\n\nLinear search: elem not found!\n\n";
    }
    else cout << "\n\nLinear search: " << index << "\n\n";
}
 
int BinarySearch(int* A, int N, int X)
{
    bool check = false;
    int left = 0, mid, right = N;
    
    while ((left <= right) && (check != true)) {
        mid = (left + right) / 2;
        if (A[mid] == X) check = true;
        if (A[mid] > X) right = mid - 1;
        else left = mid + 1;
    }
    
    
    
    if (check) return mid;
    else return -1;
}
 
int main()
{
    srand(unsigned(time(0)));
    int n; cin >> n;
    int* a = new int[n];
    
    for (int i = 0; i < n; i++) {
        a[i] = rand() % 10;
        cout << a[i] << " ";
    }
    sort(a, a+n); cout << "\n\n";
    
    for (int i = 0; i < n; i++) {
        cout << a[i] << " ";
    }
    cout << "\n\n"; 
 
    int x; cin >> x;
    
    LinearSearch(a, n, x);
    if (BinarySearch(a, n, x) == -1) {
        cout << "Binary search: elem not found!\n\n";
    }
    else { 
        cout << "Binary search: " << BinarySearch(a, n, x) << "\n\n";
    }
    
    delete[] a;
    
    system("pause");
    return 0;
}

int BinarySearch(int* A, int N, int X)
{
    bool check = false;
    int left = 0, mid, right = N;
    
    while ((left <= right) && (check != true)) {
        mid = (left + right) / 2;
        if (A[mid] == X) check = true;
        if (A[mid] > X) right = mid - 1;
        else left = mid + 1;
    }
    
    if (check) {
        while (A[mid-1] == X) mid--;
        return mid;
    }
    else return -1;
}