Find Peak Element

arraybinary search

Problem Statement

A peak element is an element that is strictly greater than its neighbors.

Given a 0-indexed integer array nums , find a peak element, and return its index. If the array contains multiple peaks, return the index to any of the peaks .

You may imagine that nums[-1] = nums[n] = -∞ . In other words, an element is always considered to be strictly greater than a neighbor that is outside the array.

You must write an algorithm that runs in O(log n) time.

Examples

Example 1

Input: nums = [1,2,3,1]
Output: 2
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: 5
Your function can return either index number 1 where the peak element is 2, or index number 5 where the peak element is 6.

Constraints

1 <= nums.length <= 1000

-2 ^31 <= nums[i] <= 2 ^31 - 1

nums[i] != nums[i + 1] for all valid i .

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicBinary Search