3Sum

Description

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]]

Example 2:

Input: nums = []
Output: []

Example 3:

Input: nums = [0]
Output: []

 

Constraints:

• 0 <= nums.length <= 3000
• -105 <= nums[i] <= 105

Solution(javascript)

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var threeSum = function(nums) {
    nums.sort((a,b) => a -b);
    const result = {};
    for(let i = 0; i < nums.length - 2; i++) {
        let left = i + 1;
        let right = nums.length - 1;
        while(left < right) {
            const sum = nums[i] + nums[left] + nums[right];
            if (sum === 0) {
                const key = nums[i].toString() + nums[left].toString()  + nums[right].toString();
                result[key] = [ nums[i] , nums[left] , nums[right] ];
            }
            
            if(sum < 0) {
                left +=1;
            } else {
                right -=1;
            }
        }
    }
    
    return Object.values(result);
};