#include <iostream>
#include <vector>

using namespace std;

int binarySearch(vector<int> [arr](https://www.google.com/search?q=arr), int [l](https://www.google.com/search?q=l), int [r](https://www.google.com/search?q=r), int [x](https://www.google.com/search?q=x)) {
   if ([r](https://www.google.com/search?q=r) >= [l](https://www.google.com/search?q=l)) {
      int mid = [l](https://www.google.com/search?q=l) + ([r](https://www.google.com/search?q=r) - [l](https://www.google.com/search?q=l)) / 2;

      if ([arr](https://www.google.com/search?q=arr)[mid] == [x](https://www.google.com/search?q=x))
         return mid;

      if ([arr](https://www.google.com/search?q=arr)[mid] > [x](https://www.google.com/search?q=x))
         return binarySearch([arr](https://www.google.com/search?q=arr), [l](https://www.google.com/search?q=l), mid - 1, [x](https://www.google.com/search?q=x));

      return binarySearch([arr](https://www.google.com/search?q=arr), mid + 1, [r](https://www.google.com/search?q=r), [x](https://www.google.com/search?q=x));
   }

   return -1;
}

int main() {
   vector<int> [arr](https://www.google.com/search?q=arr) = { 2, 3, 4, 10, 40 };
   int [n](https://www.google.com/search?q=n) = [arr](https://www.google.com/search?q=arr).size();
   int [x](https://www.google.com/search?q=x) = 10;

   int result = binarySearch([arr](https://www.google.com/search?q=arr), 0, [n](https://www.google.com/search?q=n) - 1, [x](https://www.google.com/search?q=x));

   if (result == -1)
      cout << "Element is not present in array" << endl;
   else
      cout << "Element is present at index " << result << endl;

   return 0;
}

this was the reponse I got when I asked it to code binary search in c++.

#include <iostream>
#include <vector>

using namespace std;

int binarySearch(vector<int> [arr](https://www.google.com/search?q=arr), int [l](https://www.google.com/search?q=l), int [r](https://www.google.com/search?q=r), int [x](https://www.google.com/search?q=x)) {
   if ([r](https://www.google.com/search?q=r) >= [l](https://www.google.com/search?q=l)) {
      int mid = [l](https://www.google.com/search?q=l) + ([r](https://www.google.com/search?q=r) - [l](https://www.google.com/search?q=l)) / 2;

      if ([arr](https://www.google.com/search?q=arr)[mid] == [x](https://www.google.com/search?q=x))
         return mid;

      if ([arr](https://www.google.com/search?q=arr)[mid] > [x](https://www.google.com/search?q=x))
         return binarySearch([arr](https://www.google.com/search?q=arr), [l](https://www.google.com/search?q=l), mid - 1, [x](https://www.google.com/search?q=x));

      return binarySearch([arr](https://www.google.com/search?q=arr), mid + 1, [r](https://www.google.com/search?q=r), [x](https://www.google.com/search?q=x));
   }

   return -1;
}

int main() {
   vector<int> [arr](https://www.google.com/search?q=arr) = { 2, 3, 4, 10, 40 };
   int [n](https://www.google.com/search?q=n) = [arr](https://www.google.com/search?q=arr).size();
   int [x](https://www.google.com/search?q=x) = 10;

   int result = binarySearch([arr](https://www.google.com/search?q=arr), 0, [n](https://www.google.com/search?q=n) - 1, [x](https://www.google.com/search?q=x));

   if (result == -1)
      cout << "Element is not present in array" << endl;
   else
      cout << "Element is present at index " << result << endl;

   return 0;
}

this was the reponse I got when I asked it to code binary search in c++.