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]

Constraints:

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