// Find Peak Element — MEDIUM

// Category: binary-search

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 of any of them.

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

Example: nums = [1,2,3,1]

Output: 2