链式队列的基本操作

深藏阁楼爱情的钟 2023-05-28 09:49 24阅读 0赞

操作介绍：  
1、创建一个链式队列  
2、入队一个元素  
3、出队一个元素  
4、获取队首元素  
5、清空队列  
6、判断队列是否为空  
7、求队列长度  
8、输出当前的队列  
9、退出操作系统

#include<windows.h>
    #include<iostream>
    using namespace std;
    typedef struct QNode     //结点结构
    {
        
    	int data;
    	struct QNode *next;
    }QNode, *QPtr;
    typedef struct
    {
        
    	QPtr front;   //队首指针
    	QPtr rear;    //队尾指针
    }LinkQueue;
    //函数声明
    //创建一个链式队列
    LinkQueue InitQueue()
    {
        
    	LinkQueue Q;
    	Q.front = Q.rear = (QPtr)malloc(sizeof(QNode));
    	if (Q.front == NULL)
    	{
        
    		cout << "error";   //存储分配失败
    		exit(0);
    	}
    	int n, i;
    	cout << "请输入你希望队列元素的个数：";
    	cin >> n;
    	if (n == 0)cout << endl;
    	else 
    	{
        
    		cout << "请输入" << n << "个队列元素：";
    		for (i = 0; i < n; i++)
    		{
        
    			QPtr p;
    			p = (QPtr)malloc(sizeof(QNode));
    			p->next = NULL;
    			cin >> p->data;
    			Q.rear->next = p;
    			Q.rear = p;
    		}
    	}
    	return Q;
    }
    //输出链式队列
    void putQueue(LinkQueue Q)
    {
        
    	
    	cout << "当前队列为：";
    	if (Q.front == Q.rear)
    	{
        
    		cout << "队列为空"<<endl;
    	}
    	else
    	{
        
    		QPtr p;
    		p = Q.front->next;
    		while (p != NULL)
    		{
        
    			cout << p->data << " ";
    			p = p->next;
    		}
    		cout << endl;
    	}
    }
    //入队一个元素
    LinkQueue EnQueue(LinkQueue Q)
    {
        
    	int e;
    	cout << "请输入入队元素：";
    	cin >> e;
    	QPtr p;
    	p = (QPtr)malloc(sizeof(QNode));
    	p->next = NULL;
    	p->data = e;
    	Q.rear->next = p;
    	Q.rear = Q.rear->next;
    	return Q;
    }
    //出队一个元素
    LinkQueue DeQueue(LinkQueue Q)
    {
        
    	QPtr p;
    	if (Q.front == Q.rear)
    		cout << "队空，无法完成出队操作";
    	p = Q.front->next;
    	Q.front->next = p->next;
    	free(p);
    	return Q;
    }
    //获取队首元素
    void  GetfirstQueue(LinkQueue Q)
    {
        
    	if (Q.front == Q.rear)
    		cout << "队空，无法完成获取队首元素操作";
    	else
    	{
        
    		cout << "队首元素为：";
    		cout << Q.front->next->data;
    	}
    	cout << endl;
    }
    //清空队列
    LinkQueue ClearQueue(LinkQueue Q)
    {
        
    	while (Q.front->next != Q.rear)
    	{
         
    		QPtr p;
    		p = Q.front->next;
    		Q.front->next = p->next;
    		free(p);
    	}
    	while(Q.front->next == Q.rear)
    	{
        
    		QPtr p;
    		p = Q.front->next;
    		p->next = NULL;
    		Q.rear = Q.front;
    		Q.front->next = NULL;
    		free(p);
    	}
    	return Q;
    }
    //判断队列是否空为空
    void JudgeQueue(LinkQueue Q)
    {
        
    	if (Q.front == Q.rear)cout << "队空"<<endl;
    	else cout << "队列不为空"<<endl;
    }
    //求队列长度
    void GetQueuelength(LinkQueue Q)
    {
        
    	int num = 0;
    	if (Q.front == Q.rear)num = 0;
    	QPtr p;
    	p = Q.front->next;
    	while (p)
    	{
        
    		p = p->next;
    		num++;
    	}
    	cout << "队列长度为：" << num << endl;
    }
    int main()
    {
        
    	int m;
    	LinkQueue Q;
    	while (1)
    	{
        
    		Sleep(1000);
    		cout << "*********操作介绍*********" << endl;
    		cout << "    1、创建一个链式队列    " << endl;
    		cout << "    2、入队一个元素        " << endl;
    		cout << "    3、出队一个元素        " << endl;
    		cout << "    4、获取队首元素        " << endl;
    		cout << "    5、清空队列            " << endl;
    		cout << "    6、判断队列是否空为空   " << endl;
    		cout << "    7、求队列长度          " << endl;
    		cout << "    8、输出链式队列        " << endl;
    		cout << "    9、退出操作系统        " << endl;
    		cout << "**************************" << endl;
    		cout << "请输入你的操作代号：";
    		cin >> m;
    		switch (m)
    		{
        
    		case 1:
    			Q = InitQueue();
    			break;
    		case 2:
    			Q=EnQueue(Q);
    			break;
    		case 3:
    			Q=DeQueue(Q);
    			break;
    		case 4:
    			GetfirstQueue(Q);
    			break;
    		case 5:
    			Q=ClearQueue(Q);
    			break;
    		case 6:
    			JudgeQueue(Q);
    			break;
    		case 7:
    			GetQueuelength(Q);
    			break;
    		case 8:
    			putQueue(Q);
    			break;
    		}
    		if (m == 9)break;
    	}
    	while (1);
    	return 0;
    }