content: package codingquestions.leetcode;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  
  
  /*
   * Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.
  
  Notice that the solution set must not contain duplicate triplets.
  
   
  
  Example 1:
  
  Input: nums = [-1,0,1,2,-1,-4]
  Output: [[-1,-1,2],[-1,0,1]]
  Explanation: 
  nums[0] + nums[1] + nums[2] = (-1) + 0 + 1 = 0.
  nums[1] + nums[2] + nums[4] = 0 + 1 + (-1) = 0.
  nums[0] + nums[3] + nums[4] = (-1) + 2 + (-1) = 0.
  The distinct triplets are [-1,0,1] and [-1,-1,2].
  Notice that the order of the output and the order of the triplets does not matter.
  Example 2:
  
  Input: nums = [0,1,1]
  Output: []
  Explanation: The only possible triplet does not sum up to 0.
  Example 3:
  
  Input: nums = [0,0,0]
  Output: [[0,0,0]]
  Explanation: The only possible triplet sums up to 0.
   
   * 
   * 
   */
  public class SumThree {
  
      public static void main(String[] args) {
          var sum3 = new SumThree();
          System.out.println(sum3.threeSum(new int[]{-1, 0, 1, 2, -1, -4}));
      }
  
      public List<List<Integer>> threeSum(int[] nums) {
          List<List<Integer>> list = new ArrayList<>();
  
          for (int i = 0; i < nums.length - 2; i++) {
              for (int j = i + 1; j < nums.length - 1; j++) {
                  for (int k = j + 1; k < nums.length; k++) {
                      if ((nums[i] + nums[j] + nums[k]) == 0) {
                          List<Integer> list1 = new ArrayList<>();
                          list1.add(nums[i]);
                          list1.add(nums[j]);
                          list1.add(nums[k]);
                          Collections.sort(list1);
                          if (!list.contains(list1)) {
                              list.add(list1);
                          }
                      }
                  }
              }
          }
  
          return list;
      }
  
      public List<List<Integer>> threeSumaccepted(int[] nums) {
          List<List<Integer>> res = new ArrayList<>();
          Arrays.sort(nums);
          for (int i = 0; i < nums.length - 2; i++) {
              if (i > 0 && nums[i] == nums[i - 1]) {              // skip same result
                  continue;
              }
              int j = i + 1, k = nums.length - 1;
              int target = -nums[i];
              while (j < k) {
                  if (nums[j] + nums[k] == target) {
                      res.add(Arrays.asList(nums[i], nums[j], nums[k]));
                      j++;
                      k--;
                      while (j < k && nums[j] == nums[j - 1]) j++;  // skip same result
                      while (j < k && nums[k] == nums[k + 1]) k--;  // skip same result
                  } else if (nums[j] + nums[k] > target) {
                      k--;
                  } else {
                      j++;
                  }
              }
          }
          return res;
      }
  }
  