顺序队列的操作-C语言

具体操作如下：

/*
 * queue.c
 *
 * Created on: 2010-12-21
 * Author: qiang
 */

#include <stdio.h>
#include <stdlib.h>

#define QUEUE_INIT_SIZE 5
typedef int QElemType;
typedef int Status;

typedef struct QNode{
    QElemType data;
    struct QNode *next;
}QNode;
typedef struct{
    QNode *front;    //队头

    QNode *rear;    //队尾

}SqQueue;

//队列初始化

Status Init(SqQueue* Q)
{
    Q->front = Q->rear =NULL;    //队列的头尾置空

    return 0;
}

//添加数据入队

Status QueueInsert(SqQueue *Q,QElemType e)
{
    QNode *node;    //定义新节点

    node = (QNode*)malloc(sizeof(QNode));
    if(node == NULL)
        printf("err:内存分配失败！\n");
    printf("mem of data: %p H \n",node);
    //节点赋值

    node->next = NULL;    //声明为尾节点

    node->data = e;

    //

    if(Q->rear == NULL)
        Q->front = Q->rear = node;    //队列只有一个节点

    else
    {
        Q->rear->next = node;
        Q->rear = Q->rear->next;
        printf("rear data：%d \n",Q->rear->data);
    }

    return 0;
}

//取出队头节点

Status DeQueue(SqQueue *Q,QElemType *e)
{
    if(Q->rear == Q->front)
    {
        printf("队列为空！ \n");
    }
    else
    {
        QNode *tmpNode;
        tmpNode = Q->front;
        (*e) = tmpNode->data;
        Q->front = tmpNode->next;

        //判断取出数据后是否为空

        if(tmpNode == Q->rear)
        {
            Q->front = Q->rear;
        }

        free(tmpNode);    //释放队头内存

    }
    return 0;
}

//销毁队列

Status DestroyQueue(SqQueue *Q)
{
    QNode *curNode;
    curNode = Q->front;        //指向头节点


    if(curNode)
    {
        Q->front = Q->front->next;
        free(curNode);        //释放节点内存

        curNode = Q->front;
    }
    Q->rear = Q->front = NULL;        //头尾置空


    return 0;
}

//判断队列是否为空

int QueueEmpty(SqQueue *Q)
{
    //判断队首或队尾任一个指针是否为空即可

    if(Q->front==NULL)
        return 1;
    else
        return 0;
}

Status GetHead(SqQueue *Q,QElemType *e)
{
    if(Q->front == NULL)
    {
        printf("Queue is Empty,GetHead error! \n");
        return -1;
    }
    else
    {
        (*e) = Q->front->data;
        return 0;
    }

    return 0;
}

//获取队列的长度-元素的个数

int QueueLength(SqQueue *Q)
{
    int n = 0;        //注意n的初始化

    QNode *curNode;
    curNode = Q->front;
    while(curNode)
    {
        curNode = curNode->next;
        n++;
    }

    return n;
}


int main()
{
    SqQueue Q;
    //初始化一个队列

    if(Init(&Q)!=0)
    {
        printf("Init error! \n");
        return -1;
    }
    printf("Init OK! \n");

    //插入x到队列中

    int x;
    printf("请输入插入队列的数据：\n");
    while(scanf("%d",&x)!=EOF)
    {
        printf("Insert data: %d \n",x);
        QueueInsert(&Q,x);
    }

    //打印队列中的数据

    QNode *curNode;
    curNode = Q.front;
    printf("队列中的数据为： \n");
    while(curNode!=NULL)
    {
        printf("addr: %p H ;queue data: %d \n",curNode,curNode->data);
        curNode = curNode->next;
    }

    //获得队列长度-元素的个数

    int i;
    i = QueueLength(&Q);
    printf("Length is %d \n",i);

    //读取队列头元素

    int j;
    if(!GetHead(&Q,&j))
    {
        printf("Head data: %d \n",j);
    }

    //删除队列所有元素

    if(DestroyQueue(&Q)==0)
        printf("DestroyQueue OK! \n");

    //判断是否为空

    if(QueueEmpty(&Q))
        printf("Queue is empty! \n");

    return 0;
}


结果：
qiang@LinuxSir:~/workspace/queue/Debug$ ./queue
Init OK!
请输入插入队列的数据：
1
Insert data: 1
mem of data: 0x9705008 H
2
Insert data: 2
mem of data: 0x9705018 H
rear data：2
3
Insert data: 3
mem of data: 0x9705028 H
rear data：3
队列中的数据为：
addr: 0x9705008 H ;queue data: 1
addr: 0x9705018 H ;queue data: 2
addr: 0x9705028 H ;queue data: 3
Length is 3
Head data: 1
DestroyQueue OK!
Queue is empty!

文件:	queue.zip
大小:	27KB
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