3sum.py

class Solution:
    def threeSum(self, nums: List[int]) -> List[List[int]]:
        nums.sort()
        target = []
        for i in range(len(nums)-2):
            if i > 0 and nums[i] == nums[i-1]:
                continue
            l,r = i + 1, len(nums) - 1
            while l < r:
                total = nums[i] + nums[l] + nums[r]
                if total < 0:
                    l += 1
                elif total > 0:
                    r -= 1
                else:
                    target.append([nums[i],nums[l],nums[r]])
                    while l < r and nums[l] == nums[l+1]:
                        l += 1
                    while l < r and nums[r] == nums[r-1]:
                        r -= 1
                    l += 1
                    r -= 1
        return target