July - Day 8 - Three Sum

Solution.py

# https://leetcode.com/explore/challenge/card/july-leetcoding-challenge/545/week-2-july-8th-july-14th/3384/

class Solution:
  def threeSum(self, nums: List[int]) -> List[List[int]]:
    res = set()
    nums.sort()
      
    for i in range(len(nums)):
      if nums[i] > 0:
        continue
      self.twoSum(nums, -nums[i], i, res)
    
    return list(res)
  
  def twoSum(self, nums: List[int], target: int, i: int, res: List[int]):
    start = i + 1
    end = len(nums) - 1
    
    while start < end:
      if nums[start] + nums[end] == target:
        res.add(tuple(sorted([nums[start], nums[end], -target])))
        start += 1
        end -= 1
      elif nums[start] + nums[end] < target:
        start += 1
      else:
        end -= 1