leetcode FindPeakElement

public class FindPeakElement {
    /**
     * A peak element is an element that is greater than its neighbors.
     *
     * Given an input array nums, where nums[i] ≠ nums[i+1], find a peak element and return its index.
     *
     * The array may contain multiple peaks, in that case return the index to any one of the peaks is fine.
     *
     * You may imagine that nums[-1] = nums[n] = -∞.
     *
     * Example 1:
     *
     * Input: nums = [1,2,3,1]
     * Output: 2
     * Explanation: 3 is a peak element and your function should return the index number 2.
     * Example 2:
     *
     * Input: nums = [1,2,1,3,5,6,4]
     * Output: 1 or 5
     * Explanation: Your function can return either index number 1 where the peak element is 2,
     *              or index number 5 where the peak element is 6.
     * Note:
     *
     * Your solution should be in logarithmic complexity.
     */
    public int findPeakElement(int[] nums) {
        int left = 0;
        int right = nums.length-1;
        while (left < right) {
            int mid = (left + right)/2;
            if ( !((mid-1>=0 && nums[mid]<nums[mid-1]) || (mid+1<nums.length && nums[mid] < nums[mid+1]))) {
                return mid;
            }
            if (mid-1>=0 && nums[mid-1] > nums[mid]){
                right = mid-1;
            }
            else if (mid+1>nums.length && nums[mid+1]>nums[mid]) {
                left = mid+1;
            }
        }
        return left;
    }
}