Find all unique triplets summing to zero

Q: Find all unique triplets summing to zero

This question evaluates array-based algorithm design, handling of duplicate results, and analysis of time and space complexity when producing unique triplets that sum to zero.

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Question

Problem

Given an integer array nums, return all unique triplets [nums[i], nums[j], nums[k]] such that:

i , j , and k are distinct indices ( i != j != k ), and
nums[i] + nums[j] + nums[k] == 0 .

The returned triplets must be unique (i.e., no duplicate triplets in the output). Triplets can be returned in any order.

Input

nums : an array of integers

Output

A list/array of unique triplets, each triplet containing three integers whose sum is zero

Constraints (typical interview bounds)

0 <= nums.length <= 3000
-10^5 <= nums[i] <= 10^5

Example

Input: nums = [-1, 0, 1, 2, -1, -4]
Output: [[-1, -1, 2], [-1, 0, 1]]