Rank Transform of an Array

Leetcode problem 1331; Difficulty: Easy

Problem Statement

Given an array of integers arr, replace each element with its rank.

The rank represents how large the element is. The rank has the following rules:

• Rank is an integer starting from 1.
• The larger the element, the larger the rank. If two elements are equal, their rank must be the same.
• Rank should be as small as possible.

Constraints:

• 0 <= arr.length <= 105
• -109 <= arr[i] <= 109

Example 1:

Input: arr = [40,10,20,30]

Output: [4,1,2,3]

Explanation:

 40 is the largest element. 10 is the smallest. 20 is the second smallest. 30 is the third smallest.

Example 2:

Input: arr = [100,100,100]

Output: [1,1,1]

Explanation:

Same elements share the same rank.

Example 3:

Input: arr = [37,12,28,9,100,56,80,5,12]

Output: [5,3,4,2,8,6,7,1,3]

Submitted Solution

The implemented solution received the following rating on Leetcode: