Code RoomCount triplets less than target
MediumPrep Room Coding #893

Count triplets less than target

CodingAlgorithms & data structuresMid–Senior~26 min

Given an array nums and an integer target, count the number of index triples (i, j, k) with i < j < k such that nums[i] + nums[j] + nums[k] < target. Constraints: 0 <= len(nums) <= 3500, -100 <= nums[i] <= 100, -3*10^4 <= target <= 3*10^4. Aim for O(n^2).

Implement
three_sum_smaller(nums: list[int], target: int) → int
Examples
in[[-2,0,1,3],2]out2
What 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 26 min
InputExpectedGot
[[-2,0,1,3],2]2not run yetsample