12_Three_Sum

from collections import defaultdict
class Solution:
    def threeSum(self, nums: List[int]) -> List[List[int]]:
        nums.sort()
        # d=set()
        ans=set()
        for i in range(len(nums)):
            d=set()
            for j in range(i+1,len(nums)):
                target=-1*(nums[i]+nums[j])
                if target in d:
                    triplet = [nums[i],target,nums[j]]
                    ans.add(tuple(triplet))
                d.add(nums[j])
        return ans