A peak element is an element that is strictly greater than its neighbors.
Given an integer array nums, find a peak element and return its index. If the array contains multiple peaks, return the index to any of them.
You may imagine that nums[-1] = nums[n] = -∞. You must write an algorithm that runs in O(log n) time.
Example 1:
Input: nums = [1, 2, 3, 1]
Output: 2
Explanation: 3 is a peak element and index 2 is returned.
Example 2:
Input: nums = [1, 2, 1, 3, 5, 6, 4]
Output: 5
Explanation: Either index 1 (value 2) or index 5 (value 6) can be returned.
1 <= nums.length <= 1000-2^31 <= nums[i] <= 2^31 - 1nums[i] !== nums[i + 1] for all valid i