LC: 259. 3Sum Smaller

https://leetcode.com/problems/3sum-smaller/

Question

259. 3Sum Smaller

Given an array of n integers nums and an integer target, find the number of index triplets i, j, k with 0 <= i < j < k < n that satisfy the condition nums[i] + nums[j] + nums[k] < target.

Example 1:

Input: nums = [-2,0,1,3], target = 2
Output: 2
Explanation: Because there are two triplets which sums are less than 2:
[-2,0,1]
[-2,0,3]

Example 2:

Input: nums = [], target = 0
Output: 0

Example 3:

Input: nums = [0], target = 0
Output: 0

Constraints:

• n == nums.length

• 0 <= n <= 3500

• -100 <= nums[i] <= 100

• -100 <= target <= 100

The Essence

Details and Solutions