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