Count Smaller Numbers After Self

Problem Statement
You are given an integer array nums. Return an integer array counts where counts[i] is the number of smaller elements to the right of nums[i].[1][2]

Example 1
Input: nums =[2][5][6][1] Output:[1][2] Explanation:

• To the right of 5, there are 2 smaller elements (2 and 1).
• To the right of 2, there is 1 smaller element (1).
• To the right of 6, there is 1 smaller element (1).
• To the right of 1, there are 0 smaller elements.[5][2][1]

Example 2
Input: nums = [-1]
Output:
Explanation: No elements to the right.[9]

Example 3
Input: nums = [-1,-1]
Output:
Explanation: The element to the right is equal, so not smaller.[9]

Constraints

• 1 ≤ nums.length ≤ 10^5
• -10^4 ≤ nums[i] ≤ 10^4[1]