链式队列

头文件

  1 #ifndef _QUEUELI_H
  2 #define _QUEUELI_H
  3 
  4 template<class Object>
  5 class Queue
  6 {
  7 
  8 public:
  9     Queue();
 10     ~Queue();
 11 
 12     bool isEmpty() const;
 13     const Object & getFront() const;//返回队首数据
 14     void enqueue(const Object & x);//在队尾加入数据
 15     Object dequeue();//出队
 16     void makeEmpty();
 17 private:
 18 
 19     //嵌套结构
 20     struct ListNode
 21     {
 22     
 23         Object element;//元素
 24         ListNode *next;//指针
 25 
 26         ListNode(const Object & theElement,ListNode *n = 0)
 27             :element(theElement), next(n){}
 28     
 29     };
 30 
 31     ListNode *front;
 32     ListNode *back;
 33 
 34 };
 35 
 36 template <class Object>
 37 Queue<Object>::Queue()
 38 {
 39 
 40     front = back =0;
 41     
 42 }
 43 
 44 template <class Object>
 45 Queue<Object>::~Queue()
 46 {
 47 
 48     makeEmpty();
 49     
 50 }
 51 
 52 template <class Object>
 53 void Queue<Object>::makeEmpty()
 54 {
 55 
 56     if(!isEmpty())
 57         dequeue();
 58 }
 59 
 60 template<class Object>
 61 bool Queue<Object>::isEmpty() const
 62 {
 63 
 64     return front == 0;
 65 
 66 }
 67 
 68 template <class Object>
 69 const Object & Queue<Object>::getFront() const
 70 {
 71 
 72     if(isEmpty())
 73         throw"Queue is empty";
 74     return front->element;
 75 
 76 }
 77 
 78 template <class Object>
 79 void Queue<Object>::enqueue(const Object &x)//入栈
 80 {
 81 
 82     if(isEmpty())
 83         back = front = new ListNode(x);//节点里的数据是x，第二个参数用的是缺省值，指向下一个节点的指针为零。
 84     else
 85         back = back->next = new ListNode(x);
 86 
 87 
 88 }
 89 
 90 template<class Object>
 91 Object Queue<Object>::dequeue()
 92 {
 93 
 94     Object frontItem = getFront();
 95 
 96     ListNode *old = front;//声明一个指针old用来接住要被删除的front;
 97 
 98     front = front ->next;
 99     delete old;
100 
101     return frontItem;
102 
103 
104 }
105 #endif

main.cpp

 1 #include <iostream>
 2 #include"QueueLi.h"
 3 
 4 using namespace std;
 5 
 6 int main()
 7 
 8 {
 9 
10     cout << "测试链式队列 " << endl;
11 
12     Queue<int> myQ;
13 
14     myQ.enqueue(10);
15     myQ.enqueue(20);
16     myQ.enqueue(30);
17     cout << myQ.getFront() << endl;
18     myQ.dequeue();
19     cout << myQ.getFront() << endl;
20 
21     for(int j =0; j < 8; j++)
22     {
23     
24         for(int i = 0; i< 8; i++)
25             myQ.enqueue(i);
26 
27         while(!myQ.isEmpty())
28             cout << myQ.dequeue() << endl;
29 
30     }
31 
32 
33     return 0;
34 }

转载于:https://www.cnblogs.com/uniquews/archive/2012/03/27/2420452.html