2，数组模拟队列

实现思路：

1）front=-1指向队列头前一位置，rear=-1指向队列尾，maxSize初始化队列最大容量

2）当rear<maxSize-1 表示队列还未满，允许继续在队列末尾添加rear++；

3）当front==rear表示队列为空

C#实现代码：

 1 using System;
 2 
 3 namespace 数据结构
 4 {
 5     public class ArrayQueue
 6     {
 7         private int maxSize;//队列最大值        
 8         private int front;//队列头
 9         private int rear;//队列尾
10         private int[] arrayQueue;//模拟队列数组
11         //初始化队列
12         public ArrayQueue(int maxSize = 1)
13         {
14             this.maxSize = maxSize;
15             this.arrayQueue = new int[maxSize];
16             this.front = -1;//指向队列头前一个位置
17             this.rear = -1;//指向队列尾，队列最后一个位置
18         }
19 
20         //判断队列是否已满
21         public bool IsFull()
22         {
23             return rear == maxSize - 1;
24         }
25         public bool IsEmpty()
26         {
27             return front == rear;
28         }
29 
30         //入队
31         public bool AddQueue(int item)
32         {
33             //队列已满
34             if (IsFull())
35             {
36                 Console.WriteLine("队列已满...");
37                 return false;
38             }
39             rear++;
40             arrayQueue[rear] = item;
41             return true;
42         }
43 
44         //出队
45         public int GetQueue()
46         {
47             //队列为空
48             if (IsEmpty())
49             {
50                 throw new IndexOutOfRangeException("队列为空...");
51             }
52             front++;
53             return arrayQueue[front];
54         }
55     }
56 
57     public class ArrayQueueDemo
58     {
59         static void Main(string[] args)
60         {
61             //初始化队列
62             var queue = new ArrayQueue(5);
63             try
64             {
65                 queue.GetQueue();
66             }
67             catch
68             {
69                 Console.WriteLine("队列还是空的呢...
");
70             }
71             Console.WriteLine("开始入队...
");
72             for (int i = 1; i <= 6; i++)
73             {
74                 queue.AddQueue(i);
75             }
76             Console.WriteLine("
开始出队...
");
77             for (int i = 1; i < 6; i++)
78             {
79                 Console.WriteLine(queue.GetQueue());
80             }
81             try
82             {
83                 queue.GetQueue();
84             }
85             catch
86             {
87                 Console.WriteLine("全部出队了哦...");
88             }
89         }
90     }
91 }