Solution.js

// https://leetcode.com/problems/3sum/submissions/
/*
Runtime: 250 ms, faster than 38.16% of JavaScript online submissions for 3Sum.
Memory Usage: 53 MB, less than 44.62% of JavaScript online submissions for 3Sum.
*/

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var threeSum = function (nums) {
    nums = nums.sort((a, b) => a - b);
    let result = [];
    let sum = 0;
    for (let i = 0; i < nums.length; i++) {
        let a = nums[i];
        if (i > 0 && a == nums[i - 1])
            continue;
        let right = nums.length - 1;
        let left = i + 1;
        while (left < right) {
            sum = a + nums[left] + nums[right];
            if (sum > 0)
                right--;
            else if (sum < 0)
                left++
            else {
                result.push([a, nums[left], nums[right]]);
                left++;
                while (nums[left] == nums[left - 1] && left < right)
                    left++;
            }
        }
    }
    return result;
};

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