C++数据结构之链式栈(二十一)

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本文链接： https://blog.csdn.net/qq_32642107/article/details/102749963

可以参考一下这篇文章：队列的基本操作（顺序队列、循环队列、链式队列）

main

#include <iostream>
#include "QueueLi.h"

using namespace std;


int main()
{
	cout << "测试链式队列: " << endl;

	Queue<int> myQ;

	myQ.enqueue(10);
	myQ.enqueue(20);
	myQ.enqueue(30);

	cout << myQ.getFront() << endl;
	myQ.dequeue();
	//cout << myQ.getFront() << endl;
	cout << myQ.dequeue() << endl;
	cout << myQ.dequeue() << endl;


	for(int j = 0; j < 8; j++)
	{
		for(int i = 0; i < 8; i++)
			myQ.enqueue(i);

		while(!myQ.isEmpty())
			cout << myQ.dequeue() << endl;
	}

	return 0;
}

QueueLi.h

#ifndef QUEUELI_H_
#define QUEUELI_H_


template<class Object>
class Queue
{
public:
	Queue();
	~Queue();

	bool isEmpty() const;
	const Object & getFront() const;
	void enqueue(const Object & x);
	Object dequeue();
	void makeEmpty();

private:
	struct ListNode
	{
		Object element;
		ListNode *next;

		ListNode(const Object & theElement, ListNode *n = 0)
			: element(theElement), next(n){}
	};

	ListNode *front;
	ListNode *back;
};

template<class Object>
Queue<Object>::Queue()
{
	front = back = 0;
}

template<class Object>
Queue<Object>::~Queue()
{
	makeEmpty();
}

template<class Object>
void Queue<Object>::makeEmpty()
{
	while(!isEmpty())
		dequeue();
}

template<class Object>
bool Queue<Object>::isEmpty() const
{
	return front == 0;
}

template<class Object>
const Object & Queue<Object>::getFront() const
{
	if(isEmpty())
		throw "Queue is empty.";
	return front->element;
}

template<class Object>
void Queue<Object>::enqueue(const Object &x)
{
	if(isEmpty())
		back = front = new ListNode(x);
	else
		back = back->next = new ListNode(x);
}

template<class Object>
Object Queue<Object>::dequeue()
{
	Object frontItem = getFront();

	ListNode *old = front;
	front = front->next;
	delete old;

	return frontItem;
}

#endif