solution.go

package main

import (
	"sort"
)

func threeSum(nums []int) [][]int {
	var res [][]int

	sort.Ints(nums)

	for i := 0; i < len(nums)-2; i++ {
		if i == 0 || (i > 0 && nums[i] != nums[i-1]) {
			low := i + 1
			high := len(nums) - 1
			sum := 0 - nums[i]

			for low < high {
				if (nums[low] + nums[high]) == sum {
					res = append(res, []int{nums[i], nums[low], nums[high]})
					for low < high && nums[low] == nums[low+1] {
						low++
					}
					for low < high && nums[high] == nums[high-1] {
						high--
					}
					low++
					high--
				} else if nums[low]+nums[high] > sum {
					high--
				} else {
					low++
				}
			}
		}
	}

	return res
}