Count inversions
Given an integer array nums, count the number of inversions: pairs (i, j) with i < j and nums[i] > nums[j]. Array length is up to 1e5, so an O(n^2) approach will time out. Return the count as an integer.
Implement
count_inversions(nums: list[int]) → intExamples
in
[[2,4,1,3,5]]out3What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 28 min
solution.py
InputExpectedGot
[[2,4,1,3,5]]3not run yetsample