Leetcode 852. Peak Index in a Mountain Array

#include<vector>
using namespace std;

class Solution {
public:
    
    int find_pivot(vector<int> v) {
        int s=0,e=v.size()-1;
        int mid =(s+e)/2;
        while(s<e)
        while (s < e)
	{
		if(v[mid] < v[mid+1])
     			s=mid+1;
    		else
      			e = mid;
    
		mid = (s + e) / 2;
	}
	return s;
}
    int peakIndexInMountainArray(vector<int>& arr) {
        return find_pivot(arr);
    }
};