//

// TwoSum.swift

// ConquerAlgorithm

//

// Created by Freelf on 2021/2/5.

// Copyright © 2021 Freelf. All rights reserved.

//

// 1. 两数之和

// https://leetcode-cn.com/problems/two-sum/

import Foundation

class TwoSumSolution {

func twoSum(_ nums: [Int], _ target: Int) -> [Int] {

var dict = [Int : Int]()

for i in 0 ..< nums.count {

let num = nums[i]

let wantFind = target - num

if let find = dict[wantFind] {

return [find, i]

} else {

dict[num] = i

}

}

return []

}

func twoSum2(_ nums: [Int], _ target: Int) -> [Int] {

for i in 0 ..< nums.count {

for j in i + 1 ..< nums.count {

if nums[i] + nums[j] == target {

return [i, j];

}

}

}

return []

}

}