package LeetCode;

import java.util.*;

public class LC_15v2 {
    public static void main(String[] args) {
        int[] nums = {-1, 0, 1, 2, -1, -4};
        System.out.println(threeSum(nums));
    }

    public static List<List<Integer>> threeSum(int[] nums) {
        Arrays.sort(nums);
        List<List<Integer>> res = new ArrayList<>();
        if (nums.length < 3) return res;
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] > 0) break;
            if (i > 0 && nums[i] == nums[i - 1]) continue;
            int left = i + 1;
            int right = nums.length - 1;
            while (left < right) {
                if (nums[i] + nums[left] + nums[right] == 0) {
                    ArrayList<Integer> res_tmp = new ArrayList<>();
                    Collections.addAll(res_tmp, nums[i], nums[left], nums[right]);
                    res.add(res_tmp);
                    while (left < right && nums[left] == nums[left + 1]) {
                        left++;
                    }
                    while (left < right && nums[right] == nums[right - 1]) {
                        right--;
                    }
                    left++;
                    right--;
                }else if (nums[i] + nums[left] + nums[right] > 0) right--;
                else if (nums[i] + nums[left] + nums[right] < 0) left++;
            }
        }
        return res;
    }
}