#315

Count of Smaller Numbers After Self

hard · verified · 43.3% accepted · 9,239 likes · top 25%

array · binary search · divide and conquer · binary indexed tree · segment tree · merge sort · ordered set

⊣ practice⊣ quiz⊣ open on leetcode ↗

Description

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].

Example 1:

Input: nums = [5,2,6,1]
Output: [2,1,1,0]
Explanation:
To the right of 5 there are 2 smaller elements (2 and 1).
To the right of 2 there is only 1 smaller element (1).
To the right of 6 there is 1 smaller element (1).
To the right of 1 there is 0 smaller element.

Example 2:

Input: nums = [-1]
Output: [0]

Example 3:

Input: nums = [-1,-1]
Output: [0,0]

Solution