using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        int[] nums = new int[6]{-1, 0, 1, 2, -1, -4};

        var result = new List<int[]>();

        Array.Sort(nums);

        for (int i = 0; i < nums.Length; i++)

        {

            var target = 0 - nums[i];

            var left = i + 1;

            var right = nums.Length - 1;

            while (left < right)

            {

                if (nums[left] + nums[right] == target)

                {

                    result.Add(new int[3]{nums[i], nums[left], nums[right]});

                }

                else if (nums[left] + nums[right] > target)

                {

                    right--;

                }

                else if (nums[left] + nums[right] < target)

                {

                    left++;

                }

            }

​

            while (i < nums.Length - 1 && nums[i] == nums[i + 1])

                i++;

        }

​

        Console.WriteLine(result.ToArray());

    }

}