队列的链表实现

先用结构体描述链表

typedef struct Node * link;
typedef struct Node
{
    int data;
    link next;
}node;

再用结构体描述队列

typedef struct queue *qlink;
typedef struct queue
{
    link front;
    link rear;
}queue;

写出链表的相关函数

link createlist()
{
    link head = (link)malloc(sizeof(node));
    head->next = NULL;
    return head;
}
link newnode(int data)
{
    link newnode = (link)malloc(sizeof(node));
    newnode->data = data;
    return newnode;
}
void insertlistbytail(link last,int data)//尾插法
{
    link p = (link)malloc(sizeof(node));
    p->data = data;
    p->next = NULL;
    last->next = p;
}
void deletelistbyhead(link head)//删除队首元素
{
    link q = head->next;
    head->next = q->next;
    free(q);
}
void printlist(link head)
{
    link p =head->next;
    while(p)
    {
        printf("%d\n",p->data);
        p = p->next;
    }
}

初始化队列

qlink createqueue()
{
    qlink myqueue = (qlink)malloc(sizeof(queue));
    myqueue->front = createlist();
    myqueue->rear = myqueue->front;
    return myqueue;
}

入队

void EnterQueue(qlink myqueue,int data)
{
    insertlistbytail(myqueue->rear,data);
    myqueue->rear = myqueue->rear->next;
}

出队

void DeleteQueue(qlink myqueue)
{
    deletelistbyhead(myqueue->front);
}

打印队列

void printqueue(qlink myqueue)
{
    link q = myqueue->front->next;
    while(q)
    {
        printf("%d\t",q->data);
        q = q->next;
    }
}

检测队列是否为空

void QueueEmpty(qlink myqueue)
{
    if(myqueue->front->next == 0)
    {
        printf("队列为空\n");
    }
    else
    {
        printf("队列非空\n");
    }
}

输出队首元素

int QueueFirst(qlink myqueue)
{
    printf("队首元素为：%d\n",myqueue->front->next->data);
    return myqueue->front->next->data;
}

输出队尾元素

int QueueLast(qlink myqueue)
{
    printf("队尾元素为：%d\n",myqueue->rear->data);
    return myqueue->rear->data;
}

完整代码

#include<stdio.h>
#include<stdlib.h>
#define MAX 10
typedef struct Node * link;
typedef struct Node
{
    int data;
    link next;
}node;
link createlist()
{
    link head = (link)malloc(sizeof(node));
    head->next = NULL;
    return head;
}
link newnode(int data)
{
    link newnode = (link)malloc(sizeof(node));
    newnode->data = data;
    return newnode;
}
void insertlistbytail(link last,int data)
{
    link p = (link)malloc(sizeof(node));
    p->data = data;
    p->next = NULL;
    last->next = p;
}
void deletelistbyhead(link head)
{
    link q = head->next;
    head->next = q->next;
    free(q);
}
void printlist(link head)
{
    link p =head->next;
    while(p)
    {
        printf("%d\n",p->data);
        p = p->next;
    }
}
typedef struct queue *qlink;
typedef struct queue
{
    link front;
    link rear;
}queue;
qlink createqueue()
{
    qlink myqueue = (qlink)malloc(sizeof(queue));
    myqueue->front = createlist();
    myqueue->rear = myqueue->front;
    return myqueue;
}
void EnterQueue(qlink myqueue,int data)
{
    insertlistbytail(myqueue->rear,data);
    myqueue->rear = myqueue->rear->next;
}
void DeleteQueue(qlink myqueue)
{
    deletelistbyhead(myqueue->front);
}
void printqueue(qlink myqueue)
{
    link q = myqueue->front->next;
    while(q)
    {
        printf("%d\t",q->data);
        q = q->next;
    }
}
void QueueEmpty(qlink myqueue)
{
    if(myqueue->front->next == 0)
    {
        printf("队列为空\n");
    }
    else
    {
        printf("队列非空\n");
    }
}
int QueueFirst(qlink myqueue)
{
    printf("队首元素为：%d\n",myqueue->front->next->data);
    return myqueue->front->next->data;
}
int QueueLast(qlink myqueue)
{
    printf("队尾元素为：%d\n",myqueue->rear->data);
    return myqueue->rear->data;
}
int main()
{
    qlink myqueue;
    myqueue = createqueue();
    QueueEmpty(myqueue);
    EnterQueue(myqueue,1);
    QueueEmpty(myqueue);
    EnterQueue(myqueue,2);
    EnterQueue(myqueue,3);
    EnterQueue(myqueue,4);
    EnterQueue(myqueue,5);
    EnterQueue(myqueue,6);
    DeleteQueue(myqueue);
    DeleteQueue(myqueue);
    QueueFirst(myqueue);
    QueueLast(myqueue);
    printqueue(myqueue);
    return 0;
}