LeetCode：162. Looking for peak

The peak element refers to the element whose value is strictly greater than the left and right adjacent values .

Give you an array of integers nums, Find the peak element and return its index . The array may contain multiple peaks , under these circumstances , return Any peak Just where you are .

You can assume nums[-1] = nums[n] = -∞ .

You must achieve a time complexity of O(log n) Algorithm to solve this problem .

Example 1：

 Input ：nums = [1,2,3,1]
 Output ：2
 explain ：3  Is the peak element , Your function should return its index  2.

Example 2：

 Input ：nums = [1,2,1,3,5,6,4]
 Output ：1  or  5 
 explain ： Your function can return the index  1, Its peak element is  2;
      Or return index  5,  Its peak element is  6.

Tips ：

• 1 <= nums.length <= 1000
• -2^31 <= nums[i] <= 2^31 - 1
• For all that works i There are nums[i] != nums[i + 1]

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Their thinking

1. First, find the largest element , Then return to its index
2. explain ： Why is the maximum the answer ？

• Because the title has assumed nums[-1] = nums[n] = -∞, So the peak will not appear in the first and last elements
• The left and right adjacent elements of the maximum value in the array must be less than the maximum value

Code

/** * @param {number[]} nums * @return {number} */
var findPeakElement = function(nums) {
    
    return nums.indexOf(Math.max(...nums))
};