数据结构_队列_用链表动态建立释放节点实现队列各种操作_C++实现

"mqueue.h"

#include<iostream>
using namespace std;

class NODE
{
public:
	NODE();
	int num;
	NODE* next;
};

NODE::NODE()
{
	num=0;
	next=NULL;
}

class QUEUE
{
public:
	QUEUE();
	void Push();
	void Pop();
	void Front();
	void Length();
private:
	NODE *front,*rear,*keep;
	int len;
};

QUEUE::QUEUE()
{
	keep=front=rear=NULL;
	len=0;
}

void QUEUE::Pop()
{
	cout<<"Pop Called !"<<endl<<endl;
	if(front==rear)
	{	
		if(front==NULL)
			cout<<"Queue Empty !"<<endl<<endl;
		else
		{
			delete front;
			front=rear=NULL;
			len--;
		}
	}
	else
	{
		keep=front->next;
		delete front;
		front=keep;
		len--;
	}
}

void QUEUE::Push()
{
	cout<<"Push Called !"<<endl<<endl;
	int num;
	cout<<"Please Input The Number You Want To Push In This Queue :"<<endl<<endl;
	cin>>num;
	if(rear==NULL)
		front=rear=new NODE;
	else
	{
		rear->next=new NODE;
		rear=rear->next;	
	}
	rear->num=num;
	len++;
}

void QUEUE::Front()
{
	cout<<"Front Called !"<<endl<<endl;
	if(front==NULL)
	{
		cout<<"Queue Empty !"<<endl<<endl;
		return;
	}
	cout<<"The Element At The Top Of The Queue Is : "<<front->num<<endl<<endl;
}

void QUEUE::Length()
{
	cout<<"The Length Of This Queue Is : "<<len<<endl<<endl;
}

"main.cpp"

#include<iostream>
#include"mqueue.h"
using namespace std;

int main()
{
	QUEUE q;
	char choice;
	while(1)
	{
		cout<<"Your Choice , Please :"<<endl<<endl
			<<"1 . Push"<<endl
			<<"2 . Pop"<<endl
			<<"3 . Length"<<endl
			<<"4 . Front"<<endl<<endl;
		cin>>choice;
		switch(choice)
		{
		case '1':
			q.Push();
			break;
		case '2':
			q.Pop();
			break;
		case '3':
			q.Length();
			break;
		case '4':
			q.Front();
			break;
		default:
			cout<<"Please Input The Right Choice As Shown Above !"<<endl<<endl;
			break;
		}
	}
}