队列的应用

Bertha 。 2021-09-15 06:56 365阅读 0赞

/* * chen.cpp : 定义控制台应用程序的入口点。 * */
    
    #include "stdafx.h"
    #include <iostream>
    #include <stdlib.h>
    
    using namespace std;
    typedef int QElemType;
    #define MAXNUM 255
    
    /* 定义存储信息的节点 */
    struct MessageNode {
        char            data[MAXNUM];
        struct MessageNode  *next;
    };
    
    /* 定义队列 */
    struct MyQueue {
        /* 头部指针 */
        MessageNode *front;
        /* 尾部指针 */
        MessageNode *rear;
        /* 存储的信息数量 */
        int number;
    };
    
    
    /* * 出队操作 * e元素出队 */
    void de_Queue( MyQueue *q, char message[] )
    {
        if ( q->front == q->rear )
            return;
        MessageNode *temp = q->front->next;
        if ( q->front->next == q->rear )
            q->rear = q->front;
        strcpy( message, temp->data );
        q->front->next = temp->next;
        free( temp );
    }
    
    
    /* 打印队列元素 */
    void dispalyMessage( MyQueue *q )
    {
        if ( q->front == q->rear )
            return;
        MessageNode *temp   = q->front->next;
        int     index   = 1;
        while ( temp != q->rear )
        {
            cout << index++ << " " << temp->data << endl;
            temp = temp->next;
        }
        cout << index++ << " " << temp->data << endl;
    }
    
    
    /* 初始化队列 */
    void init_Queue( MyQueue *q )
    {
        q->front    = q->rear = (MessageNode *) malloc( sizeof(MessageNode) );
        q->front->next  = NULL;
        q->number   = 0;
    }
    
    
    /* 插入元素e进入队列 */
    void en_Queue( MyQueue *q, char message[] )
    {
        MessageNode *temp = (MessageNode *) malloc( sizeof(MessageNode) );
        if ( temp )
        {
            if ( q->number < 20 )
            {
                strcpy( temp->data, message );
                temp->next  = NULL;
                q->rear->next   = temp;
                q->rear     = temp;
                q->number++;
            }else{
                char temp[MAXNUM];
                de_Queue( q, temp );
                q->number--;
                en_Queue( q, message );
            }
        }
    }
    
    
    /* 清空队列 */
    void clear( MyQueue *q )
    {
        MessageNode *temp = q->front->next;
        while ( temp )
        {
            MessageNode *tp = temp;
            temp = temp->next;
            free( tp );
        }
        temp        = q->front;
        q->front    = q->rear = NULL;
        free( temp );
    }
    
    
    /* 获取第N个数据 */
    void top_Queue( MyQueue *q, int n, char message[] )
    {
        if ( q->front == q->rear )
            return;
        MessageNode *temp   = q->front->next;
        int     index   = 1;
        while ( temp != q->rear )
        {
            if ( index == n )
            {
                cout << index << " ---- " << temp->data << endl;
                break;
            }
            temp = temp->next;
            index++;
        }
        if ( index == n )
        {
            cout << index++ << temp->data << endl;
        }
    }\
    
    void menu()
    {
        cout << "请选择操作：" << endl;
        cout << "r:接收短信" << endl;
        cout << "l:显示第i条短信" << endl;
        cout << "a:显示所有的短信" << endl;
        cout << "u:删除所有的短信" << endl;
        cout << "q:退出" << endl;
    }
    
    
    int main()
    {
        char    message[MAXNUM];
        MyQueue queue;
        init_Queue( &queue );
        while ( true )
        {
            system( "cls" );
            char index;
            menu();
            cin >> index;
            system( "cls" );
            cout << index << endl;
            switch ( index )
            {
            case 'r':
                cout << "请输入短信信息：" << endl;
                char message[MAXNUM];
                cin >> message;
                en_Queue( &queue, message );
                break;
            case 'l':
                int select_i;
    
                cout << "请输入要查询i的值：";
                cin >> select_i;
                top_Queue( &queue, select_i, message );
                /* cout<<"信息内容为："<<message<<endl; */
                break;
            case 'a':
                dispalyMessage( &queue );
                break;
            case 'd':
                int i;
                cout << "请输入要删除的i的值：";
                cin >> i;
                top_Queue( &queue, i, message );
                cout << "信息内容为：" << message << endl;
                break;
            case 'u':
                cout << "即将删除所有的值:Y/N" << endl;
                char flag;
                cin >> flag;
                if ( flag == 'Y' )
                {
                    clear( &queue );
                    cout << "删除成功" << endl;
                }else if ( flag == 'N' )
                {
                    cout << "未删除" << endl;
                }
                break;
            case 'q':
                cout << "谢谢使用" << endl;
                exit( 0 );
                break;
            }
            cout << "按任意键继续" << endl;
            system( "pause" );
        }
        system( "pause" );
        return(0);
    }