from typing import List

class Solution:
    def threeSum(self, nums: List[int]) -> List[List[int]]:
        sorted = nums.sort()
        result = []
        for i in range(0, len(nums) - 2):
            if i > 0 and nums[i] == nums[i-1]:
                i += 1
                continue
            j = i + 1
            k = len(nums) - 1
            first_num = nums[i]
            while j < k:
                second_num = nums[j]
                third_num = nums[k]
                tmp_sum = first_num + second_num + third_num
                if tmp_sum < 0:
                    j += 1
                elif tmp_sum > 0:
                    k -= 1
                elif tmp_sum == 0:
                    j += 1
                    result.append([first_num, second_num, third_num])
                    while nums[j-1] == nums[j] and j < k:
                        j += 1
                else:
                    raise ValueError("Some strange shit happened")
            i += 1
        return result


cl = Solution()
print(cl.threeSum(nums=[-1,0,1,2,-1,4]))
print(cl.threeSum(nums=[0,0,0]))
print(cl.threeSum(nums=[0,0,0,0]))