Find a Fixed Point (Value equal to index) in a given array

/*Given an array of n distinct integers sorted in ascending order, write a function that returns a Fixed Point in the array, if there is any Fixed Point present in array, else returns -1. Fixed Point in an array is an index i such that arr[i] is equal to i.*/

#include <bits/stdc++.h> 
using namespace std; 
  
int binarySearch(int arr[], int low, int high)  
{  
    if(high >= low)  
    {  
        int mid = (low + high)/2; /*low + (high - low)/2;*/
        if(mid == arr[mid])  
            return mid;  
        if(mid > arr[mid])  
            return binarySearch(arr, (mid + 1), high);  
        else
            return binarySearch(arr, low, (mid -1));  
    }  
  
    /* Return -1 if there is no Fixed Point */
    return -1;  
}  
  

int main()  
{  
    int arr[10] = {-10, -1, 0, 3, 10, 11, 30, 50, 100};  
    int n = sizeof(arr)/sizeof(arr[0]);  
    cout<<"Fixed Point is "<< binarySearch(arr, 0, n-1);  
    return 0;  
}  
  
// This code is contributed by saurabh negi