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Three Sum to Zero
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Three Sum to Zero

HardPython

Problem

Given an integer array, find all unique triplets that sum to zero.

Implement three_sum(nums), returning a list of triplets. Each triplet must contain values in nondecreasing order, and the result must not contain duplicate triplets. The result order should follow the sorted traversal produced by the standard two-pointer approach.

Input is a list of integers. The function returns a list of three-element lists. Return an empty list when no valid triplet exists.

Constraints

  • 0 <= len(nums) <= 300
  • -10^5 <= nums[i] <= 10^5
  • Each returned triplet must be sorted in nondecreasing order
  • Duplicate value triplets are not allowed

Function Signature

def three_sum(nums):
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