#include<stdio.h>
#include<Stdlib.h>
typedef int  elemtype;
typedef struct QueueNode
{
    elemtype data;
    struct QueueNode *next;
}LinkedQueueNode;
typedef struct LQueue
{
    LinkedQueueNode *front;
    LinkedQueueNode *rear;
}LQueue, * LinkedQueue;

LinkedQueue Init_LinkedQueue();
 
int LinkedQueue_Empty(LinkedQueue Q);
int Enter_LinkedQueue(LinkedQueue Q,elemtype x);
int Delete_LinkedQueue(LinkedQueue Q,elemtype *x);
int GetFront_LinkedQueue(LinkedQueue Q,elemtype *x);
int Print_LinkedQueue(LinkedQueue Q);

void menu()
{   system("cls");
    printf("\t\t1-創建\n");
    printf("\t\t2-入隊\n
 
");;
    printf("\t\t3-判斷隊列是否為空\n");
    printf("\t\t4-出隊\n");
    printf("\t\t5-查看隊頭元素\n");
    printf("\t\t6-輸出\n");
    printf("\t\t#-quit\n");
    printf("Please select:  ");
}

int main()
{
    char cmd;
    int isdo;
    LinkedQueue Q;
    elemtype x;
    system("cls");
    menu();
    while((cmd=getchar())!=‘
 
#‘)
    {    switch(cmd)
        {    case ‘1‘:
                    Q=Init_LinkedQueue();
                    if(Q==NULL)
                        {
                            printf("申請鏈隊列內存空間失敗，程序結束");
                            return 0;        
                        }
                        printf("\n創建成功!\n");
                        printf("\n\n\n\t\t\t");
                        break;
            case ‘2‘:
                        printf("輸入隊列元素:\n");
                        scanf("%d",&x);
                        while(x!=0)
                        {
                            isdo= Enter_LinkedQueue(Q,x);
                            scanf("%d",&x);
                        }
                        if(isdo==1)
                        {
                            printf("入隊成功");
                        }
                        else
                        {
                            printf("入隊失敗"); 
                        }
                        printf("\n");
                        printf("\n\n\n\t\t\t");
                        break;
            case ‘3‘: 
                        isdo=LinkedQueue_Empty(Q);
                        if(isdo==1)
                        {
                            printf("隊列為空\n");
                        }
                        else if(isdo==0)
                        {
                            printf("隊列不為空\n");
                        }
                        printf("\n");
                        printf("\n\n\n\t\t\t");
                        break;
            case ‘4‘:

                    isdo=Delete_LinkedQueue(Q,&x);
                    if(isdo==1)
                    {
                        printf("出隊成功，出隊的元素為:%d\n",x);
                    }
                    else if(isdo==0)
                    {
                        printf("出隊失敗\n");
                    }
                    printf("\n");
                    printf("\n\n\n\t\t\t");
                    break;
            case ‘5‘:
                    isdo=GetFront_LinkedQueue(Q,&x);
                    if(isdo==1)
                    {
                        printf("隊頭元素為:%d\n",x);
                    }
                    else if(isdo==0)
                    {
                        printf("取隊頭元素失敗\n");
                    }
                    printf("\n");
                    printf("\n\n\n\t\t\t");
                    break;
            case ‘6‘:
                    isdo=Print_LinkedQueue(Q);                
                    printf("\n");
                    printf("\n\n\n\t\t\t");
                    break;                                                                  
        }
    fflush(stdin);
    system("pause");
    menu();
    } 
    return 0;
}
//初始化
LinkedQueue Init_LinkedQueue()
{
    LinkedQueue Q=(LinkedQueue)malloc(sizeof(LQueue));
    LinkedQueueNode *head=(LinkedQueueNode *)malloc(sizeof(LinkedQueueNode));
    if(head!=NULL&&Q!=NULL)
    {
        head->next=NULL;
        Q->front=head;
        Q->rear=head;
    }
    return  Q;
}
//判隊列空
int LinkedQueue_Empty(LinkedQueue Q)
{
    if(Q->front==Q->rear)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}
//入隊 
int Enter_LinkedQueue(LinkedQueue Q,elemtype x)
{
    LinkedQueueNode *node;
    node=(LinkedQueueNode *)malloc(sizeof(LinkedQueueNode));
    if(node==NULL)
    {
        return 0;
    }
    node->data=x;
    node->next=NULL;
    Q->rear->next=node;            //將新結點插入隊尾
    Q->rear=node;                //設置尾指針指向新的隊尾元素
    return 1;
}
//出隊
int Delete_LinkedQueue(LinkedQueue Q,elemtype *x)
{
    LinkedQueueNode *node;
    if(Q->front==Q->rear)
    {
        return 0;
    }
    else
    {
        node=Q->front->next;
        *x=node->data;
        Q->front->next=node->next;
        if(node==Q->rear)
        {
            Q->rear=Q->front;
        }
        free(node);
        return 1;
    }
}
//取隊列頭數據元素
int GetFront_LinkedQueue(LinkedQueue Q,elemtype *x)
{
    if(Q->front==Q->rear)
    {
        return 0;
    }
    else
    {
        *x=Q->front->next->data;
        return 1;
    }
}
//輸出
int Print_LinkedQueue(LinkedQueue Q)
{
    LinkedQueueNode *p;
    if(Q->front==Q->rear)
    {
        return 0;
    }
    p=Q->front->next;
    while(p->next!=0)
    {
        printf("%4d\n",p->data);
        p=p->next;
    }
    return 1;
}

鏈隊列基本操作