HTMLify

class Solution {
public:
    int findPeakElement(vector<int>& arr) {
    int n =arr.size();
    if(n == 1) return 0;
    if(arr[0] > arr[1]) return 0;
    if(arr[n-1] > arr[n-2]) return n-1;

    int start = 1, end = n-2;

    while(start<=end){
        int mid = start +(end - start) / 2;

        if(arr[mid] > arr[mid - 1] && arr[mid] > arr[mid+1]){
            return mid;
        }
        else if(arr[mid] > arr[mid-1]){
            start = mid + 1;
        }
        else {
            end = mid - 1;
        }
    }
    return -1;
    }
};