15_3Sum.py

class Solution:
    def threeSum(self, nums: List[int]) -> List[List[int]]:
        nums.sort()
        res=[]
        for i, elem in enumerate(nums):
            if i>0 and  elem == nums[i-1]:
                continue

            left = i+1
            right = len(nums)-1
            while left<right:
                tree_sum = elem + nums[right] + nums[left]
                if tree_sum > 0:
                    right-=1
                elif tree_sum <0:
                    left+=1
                else:
                    res.append([elem, nums[right], nums[left]])
                    while left < right and nums[left] == nums[left + 1]:
                        left += 1
                    while left < right and nums[right] == nums[right - 1]:
                        right -= 1
                    
                    left += 1
                    right -= 1
        return res