Find_Peak_Element.java

class Solution {
    public int findPeakElement(int[] nums) {
        if(nums.length == 1){
            return 0;
        }
        else if(nums[0] > nums[1]){
            return 0;
        }
        else if(nums[nums.length - 1] > nums[nums.length - 2]){
            return nums.length - 1;
        }
        else{
            int start = 1;
            int end = nums.length - 2;

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

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