Last updated on October 25th, 2024 at 10:20 pm

Here, We see Find Peak Element LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Find Peak Element LeetCode Solution

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.

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

1. Find Peak Element LeetCode Solution C++

class Solution {
public:
    int findPeakElement(vector<int>& nums) {
        int n = nums.size();
        for(int i=0; i<n-1; i++){
            if(nums[i] > nums[i+1]){
                return i;
            }
        }
        return n-1;        
    }
};

2. Find Peak Element LeetCode Solution Java

class Solution {
    public int findPeakElement(int[] nums) {
		if(nums.length == 1) return 0;
        int n = nums.length;
        if(nums[0] > nums[1]) return 0;
        if(nums[n-1] > nums[n-2]) return n-1;
        int start = 1;
        int end = n-2;
        while(start <= end) {
            int mid = start + (end - start)/2;
            if(nums[mid] > nums[mid-1] && nums[mid] > nums[mid+1]) return mid;
            else if(nums[mid] < nums[mid-1]) end = mid - 1;
            else if(nums[mid] < nums[mid+1]) start = mid + 1;
        }
        return -1;      
    }
}

3. Find Peak Element LeetCode Solution JavaScript

var findPeakElement = function(nums) {
    let left = 0, right = nums.length-1, mid;
    while(left < right) {
        mid = Math.floor((right+left)/2);
        if(nums[mid] > nums[mid+1]) right = mid;
        else left = mid+1;
    }
    return left;
};

4. Find Peak Element LeetCode Solution Python

class Solution(object):
    def findPeakElement(self, nums):
        left = 0
        right = len(nums)-1
        while left < right-1:
            mid = (left+right)/2
            if nums[mid] > nums[mid+1] and nums[mid] > nums[mid-1]:
                return mid
            if nums[mid] < nums[mid+1]:
                left = mid+1
            else:
                right = mid-1
        return left if nums[left] >= nums[right] else right