Binary Search on Sorted Array

From geekforgeeks.

//iterative

int binarySearch(int arr[], int l, int r, int x)
{
  while (l <= r)
  {
    int m = l + (r-l)/2;
 
    if (arr[m] == x) return m;  // Check if x is present at mid
 
    if (arr[m] < x) l = m + 1; // If x greater, ignore left half
 
    else r = m - 1; // If x is smaller, ignore right half
  }
  return -1; // if we reach here, then element was not present
}

// A recursive binary search function. It returns location of x in
// given array arr[l..r] is present, otherwise -1
int binarySearch(int arr[], int l, int r, int x)
{
   if (r >= l)
   {
        int mid = l + (r - l)/2;
 
        // If the element is present at the middle itself
        if (arr[mid] == x)  return mid;
 
        // If element is smaller than mid, then it can only be present
        // in left subarray
        if (arr[mid] > x) return binarySearch(arr, l, mid-1, x);
 
        // Else the element can only be present in right subarray
        return binarySearch(arr, mid+1, r, x);
   }
 
   // We reach here when element is not present in array
   return -1;
}