var threeSum = function (nums) {
if (nums.length < 3) return [];
nums.sort((a, b) => a - b);
for (let i = 0; i < nums.length; i++) {
//nums is sorted,so it's impossible to have a sum = 0
// skip duplicated result without set
if (i > 0 && nums[i] === nums[i - 1]) continue;
let right = nums.length - 1;
// we want to find the triplet [i, left, right] which sum to 0
// since left < right, and left > i, no need to compare i === left and i === right.
if (nums[left] + nums[right] + nums[i] === 0) {
list.push([nums[left], nums[right], nums[i]]);
// skip duplicated result without set
while (nums[left] === nums[left + 1]) {
// skip duplicated result without set
while (nums[right] === nums[right - 1]) {
} else if (nums[left] + nums[right] + nums[i] > 0) {