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.
The array may contain multiple peaks, in that case return the index to any one of the peaks is fine.

• Time: O(n)
• Space: O(1)

public int findPeakElement(int[] nums) {
    int lo = 0, hi = nums.length - 1;
    while (lo < hi) {
        int mid = (lo + hi) / 2;
        if (nums[mid] < nums[mid + 1]) {
            lo = mid + 1;
        } else {
            hi = mid;
        }
    }
    return lo;
}