LeetCode #15 - 3Sum

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

vector<vector<int>> threeSum(vector<int>& nums) {
    sort(nums.begin(), nums.end());
    vector<vector<int>> result;
    for (int i = 0; i < nums.size() - 2; i++) {
        if (i > 0 && nums[i] == nums[i - 1]) continue;
        int left = i + 1, right = nums.size() - 1;
        while (left < right) {
            int total = nums[i] + nums[left] + nums[right];
            if (total < 0) {
                left++;
            } else if (total > 0) {
                right--;
            } else {
                result.push_back({nums[i], nums[left], nums[right]});
                while (left < right && nums[left] == nums[left + 1]) left++;
                while (left < right && nums[right] == nums[right - 1]) right--;
                left++;
                right--;
            }
        }
    }
    return result;
}

int main() {
    vector<int> nums = {-1, 0, 1, 2, -1, -4};
    vector<vector<int>> result = threeSum(nums);
    for (const auto& triplet : result) {
        cout << "[" << triplet[0] << ", " << triplet[1] << ", " << triplet[2] << "]\n";
    }
    return 0;
}

package main

import (
    "fmt"
    "sort"
)

func threeSum(nums []int) [][]int {
    sort.Ints(nums)
    result := [][]int{}
    n := len(nums)
    for i := 0; i < n-2; i++ {
        if i > 0 && nums[i] == nums[i-1] {
            continue
        }
        left, right := i+1, n-1
        for left < right {
            total := nums[i] + nums[left] + nums[right]
            if total < 0 {
                left++
            } else if total > 0 {
                right--
            } else {
                result = append(result, []int{nums[i], nums[left], nums[right]})
                for left < right && nums[left] == nums[left+1] {
                    left++
                }
                for left < right && nums[right] == nums[right-1] {
                    right--
                }
                left++
                right--
            }
        }
    }
    return result
}

func main() {
    fmt.Println(threeSum([]int{-1, 0, 1, 2, -1, -4}))
}

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class ThreeSum {
    public static List<List<Integer>> threeSum(int[] nums) {
        Arrays.sort(nums);
        List<List<Integer>> result = new ArrayList<>();
        for (int i = 0; i < nums.length - 2; i++) {
            if (i > 0 && nums[i] == nums[i - 1]) continue;
            int left = i + 1;
            int right = nums.length - 1;
            while (left < right) {
                int total = nums[i] + nums[left] + nums[right];
                if (total < 0) {
                    left++;
                } else if (total > 0) {
                    right--;
                } else {
                    result.add(Arrays.asList(nums[i], nums[left], nums[right]));
                    while (left < right && nums[left] == nums[left + 1]) left++;
                    while (left < right && nums[right] == nums[right - 1]) right--;
                    left++;
                    right--;
                }
            }
        }
        return result;
    }
    public static void main(String[] args) {
        System.out.println(threeSum(new int[]{-1, 0, 1, 2, -1, -4}));
    }
}

function threeSum(nums) {
    nums.sort((a, b) => a - b);
    const result = [];
    for (let i = 0; i < nums.length - 2; i++) {
        if (i > 0 && nums[i] === nums[i - 1]) continue;
        let left = i + 1;
        let right = nums.length - 1;
        while (left < right) {
            const total = nums[i] + nums[left] + nums[right];
            if (total < 0) {
                left++;
            } else if (total > 0) {
                right--;
            } else {
                result.push([nums[i], nums[left], nums[right]]);
                while (left < right && nums[left] === nums[left + 1]) left++;
                while (left < right && nums[right] === nums[right - 1]) right--;
                left++;
                right--;
            }
        }
    }
    return result;
}

// Example usage
console.log(threeSum([-1, 0, 1, 2, -1, -4]));

<?php
function threeSum($nums) {
    sort($nums);
    $result = [];
    for ($i = 0; $i < count($nums) - 2; $i++) {
        if ($i > 0 && $nums[$i] == $nums[$i - 1]) continue;
        $left = $i + 1;
        $right = count($nums) - 1;
        while ($left < $right) {
            $total = $nums[$i] + $nums[$left] + $nums[$right];
            if ($total < 0) {
                $left++;
            } elseif ($total > 0) {
                $right--;
            } else {
                $result[] = [$nums[$i], $nums[$left], $nums[$right]];
                while ($left < $right && $nums[$left] == $nums[$left + 1]) $left++;
                while ($left < $right && $nums[$right] == $nums[$right - 1]) $right--;
                $left++;
                $right--;
            }
        }
    }
    return $result;
}

// Example usage
print_r(threeSum([-1, 0, 1, 2, -1, -4]));
?>

def three_sum(nums):
    nums.sort()
    result = []
    for i in range(len(nums) - 2):
        if i > 0 and nums[i] == nums[i - 1]:
            continue
        left, right = i + 1, len(nums) - 1
        while left < right:
            total = nums[i] + nums[left] + nums[right]
            if total < 0:
                left += 1
            elif total > 0:
                right -= 1
            else:
                result.append([nums[i], nums[left], nums[right]])
                while left < right and nums[left] == nums[left + 1]:
                    left += 1
                while left < right and nums[right] == nums[right - 1]:
                    right -= 1
                left += 1
                right -= 1
    return result

# Example usage
print(three_sum([-1, 0, 1, 2, -1, -4]))