Leetcode1131 . Rank Transform of an Array

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.

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]

先用个数组，复制，排序过来，然后再map一下，最后导出rank即可

Runtime: 22 ms, faster than 99.26% of Java online submissions for Rank Transform of an Array.

Memory Usage: 60.6 MB, less than 69.09% of Java online submissions for Rank Transform of an Array.