Replace Elements with Greatest Element on Right Side

Leetcode problem 1299; Difficulty: Easy

Problem Statement

Given an array arr, replace every element in that array with the greatest element among the elements to its right, and replace the last element with -1.

After doing so, return the array.

Constraints:

• 1 <= arr.length <= 10000
• 1 <= arr[i] <= 100000

Example 1:

Input: arr = [17,18,5,4,6,1]

Output: [18,6,6,6,1,-1]

Explanation:

- index 0 --> the greatest element to the right of index 0 is index 1 (18).
- index 1 --> the greatest element to the right of index 1 is index 4 (6).
- index 2 --> the greatest element to the right of index 2 is index 4 (6).
- index 3 --> the greatest element to the right of index 3 is index 4 (6).
- index 4 --> the greatest element to the right of index 4 is index 5 (1).
- index 5 --> there are no elements to the right of index 5, so we put -1.

Example 2:

Input: arr = [400]

Output: [-1]

Explanation:

There are no elements to the right of index 0.

Submitted Solution

The implemented solution received the following rating on Leetcode: