Find the rotation count in clockwise rotated sorted array(method -2)

Question -

To calculate the no of clockwise rotation in sorted and rotated array

Example - 

Input : arr[]  = {4,5,1,2,3} , n=5

Output : 2

Input : arr[] = {10,12,14,2,5} n=5

Output : 3

Approach - 

first we calculate pivot element of rotated and sorted array, and index of pivot element +1 is the no of rotation.

Implementation - 

//using binary search

#include<iostream>

using namespace std;

int countrotation(int arr[],int n)

{

    int low=0;

    int high=n-1;

    int mid;

    while(low<=high){

        mid=(low+high)/2;

         if(mid<high&&arr[mid]>arr[mid+1])

        return mid;

        if(mid>low&&arr[mid]<arr[mid-1])

        return mid-1;

        if(arr[low]>arr[mid])

        high=mid-1;

        else

        low=mid+1;

    }

}

int main()

{

    int n;

    cout<<"Enter the no of element : ";cin>>n;

    int arr[n];

    cout<<"Enter elements : "<<endl;

    for(int i=0;i<n;i++)

    cin>>arr[i];

    int count=countrotation(arr,n);

    cout<<"No of rotation is : "<<count+1<<endl;

    

    return 0;

    

}

Time complixity - O(logn)

code on compiler