LeetCode Find Peak Element

A peak element is an element that is greater than its neighbors.

Given an input array where num[i] ≠ num[i+1], find a peak element and return its index.

You may imagine that num[-1] = num[n] = -∞.

For example, in array [1, 2, 3, 1], 3 is a peak element and your function should return the index number 2.

public class Solution {
    public int findPeakElement(int[] num) {
        int peak = Integer.MIN_VALUE;
        int res = 0;
        for (int i = 1; i < num.length - 1; i++) {
            if (num[i] > num[i - 1] && num[i] > num[i + 1]&&num[i]>peak) {
                res = i;
                peak = num[i];
            }
        }
        if (num[0] > num[res] && num[0] > num[num.length - 1]) {
            return 0;
        } else if (num[num.length - 1] > num[0] && num[num.length - 1] > num[res]) {
            return num.length - 1;
        }else return res;
    }
}