class Solution {
public List<List<Integer>> threeSum(int[] nums) {
    Arrays.sort(nums);
    List<List<Integer>> L = new LinkedList<List<Integer>> ();
    Set<int[]> set = new HashSet<int[]> () ;
    int i = 0;
    int j , z;
    int sum = -1;
    while(i < nums.length-2){
        j = i + 1;
        z = nums.length-1;
        while(j < z){
          sum  = nums[i] + nums[j] + nums[z];
          if(sum < 0)
              j++;
          else if(sum > 0)
              z--;
            else if (sum == 0){
                set.add( new int[] { nums[i], nums[j] , nums[z]} );
                break;
            }

        }
        i++;
    }
    for( int[] each : set){
        L.add(Arrays.asList(each[0], each[1], each[2]));
    }

    return L;

}