[LeetCode] #162 Find Peak Element

public class Solution {
    public int findPeakElement(int[] nums) {
        if (nums == null || nums.length == 0) {
            return -1;
        }
        
        int start = 0;
        int end = nums.length - 1;
        while (start + 1 < end) {
            int mid = start + (end - start) / 2;
            if (mid >= 1 && nums[mid - 1] < nums[mid] && mid < nums.length - 2 && nums[mid] > nums[mid + 1] ) {
                return mid;
            } else if (mid >= 1 && nums[mid - 1] < nums[mid]) {
                start = mid;
            } else {
                end = mid;
            }
        }
        
        return nums[start] > nums[end] ? start : end;
        
    }
}