队列（链表实现）

#ifndef QUEUE_H#define QUEUE_H#include<iostream>template<typename T>struct Node{T data;struct Node *next;};template<typename T>class Queue{Node<T> *head;Node<T> *tail;int length;public:Queue();~Queue();bool IsFull()const; int enqueue(T elem);int dequeue();bool IsEmpty()const;int getLength()const;T getHead()const;T getTail()const;};template<typename T>Queue<T>::Queue(){head=new Node<T>;head->data=0;head->next=NULL;tail=head;length=0;}template<typename T>Queue<T>::~Queue(){delete head;}template<typename T>bool Queue<T>::IsFull()const{try{Node<T> *tmp=new Node<T>;delete tmp;return false;}catch(std::bad_alloc exceptin){return true;}}template<typename T>int Queue<T>::enqueue(T elem){if(length==0){head->data=elem;head->next=NULL;tail=head;}else{if(!IsFull()){Node<T> *tmp=new Node<T>;tmp->data=elem;tmp->next=NULL;tail->next=tmp;tail=tail->next;}}++length;return 0;}template<typename T>bool Queue<T>::IsEmpty()const{if(length==0&&head==tail)return true;else return false;}template<typename T>int Queue<T>::dequeue(){if(IsEmpty())return -1;else if(length==1){head->data=0;--length;return 0;}else{if(!IsFull()){Node<T> *tmp=head;head=head->next;delete tmp;--length;return 0;}}}template<typename T>int Queue<T>::getLength()const{return length;}template<typename T>T Queue<T>::getHead()const{return head->data;}template<typename T>T Queue<T>::getTail()const{return tail->data;}#endif 

// queue.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include "queue.h"using namespace std;int _tmain(int argc, _TCHAR* argv[]){Queue<int> A;int i=9;while(i!=0){A.enqueue(i);--i;}cout<<A.getLength()<<" "<<A.getHead()<<" "<<A.getTail()<<"/n";A.dequeue();cout<<A.getLength()<<" "<<A.getHead()<<" "<<A.getTail()<<"/n";system("pause");return 0;}