MergeTwoSortedArray.swift

//
// MergeTwoSortedArray.swift
// Array
//
// Created by ggl on 2019/3/21.
// Copyright © 2019年 ggl. All rights reserved.
//

import Foundation

/// 合并两个有序数组为一个有序数组
///
/// - Parameters:
/// - arrOne: 第一个有序数组
/// - arrOneCount: 第一个有序数组的大小
/// - arrTwo: 第二个有序数组
/// - arrTwoCount: 第二个有序数组的大小
/// - Returns: 新的有序数组(需要释放)
func mergeTwoSortedArray(arrOne: UnsafePointer<Int>, arrOneCount: Int, arrTwo: UnsafePointer<Int>, arrTwoCount: Int) -> UnsafePointer<Int> {
 let newArray = UnsafeMutablePointer<Int>.allocate(capacity: arrOneCount + arrTwoCount)
 
 var i = 0, j = 0
 for index in 0..<(arrOneCount + arrTwoCount) {
 //判断i和j有没有到头
 if i > arrOneCount-1 {
 newArray[index] = arrTwo[j]
 j += 1
 } else if j > arrTwoCount-1 {
 newArray[index] = arrOne[i]
 i += 1
 } else {
 let num1 = arrOne[i]
 let num2 = arrTwo[j]
 if num1 > num2 {
 newArray[index] = num2
 j += 1
 } else {
 newArray[index] = num1
 i += 1
 }
 }
 }
 return UnsafePointer(newArray)
}


/// 打印数组内容
///
/// - Parameter arr: 数组
func printArray(arr: UnsafePointer<Int>, count: Int) {
 if count == 0 {
 print("[]")
 return
 }
 
 print("[", terminator: "")
 for i in 0..<count {
 if i == count - 1 {
 print(arr[count-1], terminator: "]\n")
 } else {
 print(arr[i], terminator: " ")
 }
 }
}