main.cpp

#include <iostream>
#include <bits/stdc++.h>

using namespace std;

class Solution
{
public:
    vector<vector<int>> threeSum(vector<int> &nums)
    {
        vector<vector<int>> res;
        if (nums.size() < 3)
            return res;
        sort(nums.begin(), nums.end());
        for (int i = 0; i < nums.size() - 2; i++)
        {
            if (i > 0 && nums[i] == nums[i - 1])
                continue;
            int l = i + 1, r = nums.size() - 1;
            while (l < r)
            {
                int sum = nums[i] + nums[l] + nums[r];
                if (sum == 0)
                {
                    res.push_back({nums[i], nums[l], nums[r]});
                    while (l < r && nums[l] == nums[l + 1])
                        l++;
                    while (l < r && nums[r] == nums[r - 1])
                        r--;
                    l++;
                    r--;
                }
                else if (sum < 0)
                {
                    l++;
                }
                else
                {
                    r--;
                }
            }
        }
        return res;
    }
};

int main()
{
    Solution s;
    vector<int> nums = {-1, 0, 1, 2, -1, -4};
    vector<vector<int>> res = s.threeSum(nums);
    for (auto i : res)
    {
        for (auto j : i)
        {
            cout << j << " ";
        }
        cout << endl;
    }
    return 0;
}