Rank Transform of an Array
To solve this problem, follow these steps:
 First, make a copy of the array and sort it.
 Create a dictionary to keep track of the rank of each number. Initialize the rank to 1.
 Iterate over the sorted array. If the number is not in the dictionary, add it and its rank to the dictionary and increment the rank.
 Finally, replace each element in the original array with its rank from the dictionary.
Here’s the code:


In this code, sorted(set(arr))
creates a sorted list of unique elements in arr
. {v: i + 1 for i, v in enumerate(sorted_arr)}
maps each number to its rank. And [rank_dict[i] for i in arr]
replaces each number in arr
with its rank.