leetcode-go/easy/167.go

package main

import (
	"fmt"
)

func twoSumOld(numbers []int, target int) []int {
	for i := 0; i < len(numbers)-1; i++ {
		for j := i + 1; j < len(numbers); j++ {
			if numbers[i]+numbers[j] == target {
				return []int{i + 1, j + 1}
			}
		}
	}
	return nil
}

func twoSum(numbers []int, target int) []int {
	left, right := 0, len(numbers)-1
	for left != right {
		sum := numbers[left] + numbers[right]
		if sum < target {
			left++
		} else if sum > target {
			right--
		} else {
			return []int{left + 1, right + 1}
		}
	}
	return nil
}

func main() {
	arr := []int{-1, 0}
	fmt.Println(twoSum(arr, -1))
}