头删，尾插

#include<stdio.h>
#include<stdlib.h> 
typedef struct Queue
{
    int num;
    struct Queue *next;
}Queue;

typedef struct pQueue
{
    Queue *first;
    Queue *tail; 
} pQueue;

int getNum()
{
    int num;
    printf("请输入数字：");
    scanf("%d",&num);
    return num;
}

pQueue* creatQueue(pQueue *queueHead)    //创建链表
{
    if (queueHead==NULL)
    {
        queueHead=(pQueue *)malloc(sizeof(pQueue));
        queueHead->first=queueHead->tail=NULL;
        return queueHead;
    }
    return queueHead;
}

void tailInsertData(pQueue *queueHead)           //尾插
{
    if(queueHead==NULL)
    {
        printf("没有创建成功\n");
        return ;
    }
    Queue *p=(Queue *)malloc(sizeof (Queue));
    p->num=getNum();
    if(queueHead->first==NULL)
    {
        queueHead->first=p;
        queueHead->tail=p;
        p->next=NULL;
        return;
    }
    p->next=NULL;
    queueHead->tail->next=p;
    queueHead->tail=p; 
}

void headDeleteDta(pQueue *queueHead)                        //头删
{
    if(queueHead==NULL||queueHead->tail==NULL)
    {
        printf("无信息可删！\n");
        return ; 
    }
    if(queueHead->first->next==NULL)
    {
        free(queueHead->first);
        queueHead->first=queueHead->tail=NULL;
        return;
    }
    Queue *p=queueHead->first;
    queueHead->first=p->next;
    free(p);
    p=NULL;
}


void printData(pQueue *queueHead)                          //打印信息 
{
    if(queueHead==NULL||queueHead->tail==NULL)
    {
        printf("无信息可打印\n");
        return;
        
    }
    Queue *temp;
    printf("Head-->");
    for(temp=queueHead->first; temp!=NULL; temp=temp->next)
    {
        printf("[%d]-->",temp->num);
    }
    printf("NULL\n");
} 
int main()
{
    pQueue *queueHead=NULL;
    int select;
    while(1)
    {
        printf("=======\n");
        printf("1.创建数据\n");
        printf("2.删除数据\n");
        printf("3.插入数据\n");
        printf("4.打印队列\n");
        printf("5.退出\n");
        printf("=======\n");
        scanf("%d",&select);
        switch(select)
        {
            case 1:
                queueHead=creatQueue(queueHead);
                break;
            case 2:
                headDeleteDta(queueHead);
                break;
            case 3:
                tailInsertData(queueHead);
                break;              
            case 4:
                printData(queueHead);
                break;              
            case 5:
            
                return 0;
            default:
                break;                              
        }       
        
    }


    return 0;
}