数据结构 -- 链队列

工程目录结构图:

common.h:

//#ifndef __common_h__
//#define __common_h__

#define OK 1
#define ERROR 0
#define TRUE 1
#define FALSE 0 

#define MAXSIZE 20

typedef int Status;        //函数的返回结果，OK、ERREO、TRUE、FALSE
typedef int ElemType;   //结点数据域的数据类型

//#endif

common.c:

#include "common.h"

Status visit(ElemType e)
{
    printf("%d , ", e);
    return OK;
}

LinkQueue.h:

//链队列结点结构
typedef struct QNode
{
    ElemType data;
    struct QNode *next;
}QNode, *QNodePtr;

//链队列,带有头结点
typedef struct
{
    QNodePtr front, rear;
}LinkQueue;

LinkQueue.c:

#include <stdio.h>
#include <malloc.h>
#include "common.h"
#include "LinkQueue.h"

Status InitLinkQueue(LinkQueue *Q)
{
    Q->front = Q->rear = (QNodePtr)malloc(sizeof(QNode));
    if (!Q->front)
        return FALSE;
    Q->front->next = NULL;
    return OK;
}

Status LinkQueueEmpty(LinkQueue Q)
{
    if (Q.front == Q.rear)
        return TRUE;
    else
        return FALSE;
}

int GetLinkQueueLegth(LinkQueue Q)
{
    int length = 0;

    QNodePtr ptr = Q.front;
    while (ptr != Q.rear)
    {
        ++length;
        ptr = ptr->next;
    }

    return length;
}

Status EnLinkQueue(LinkQueue *Q, ElemType e)
{
    QNodePtr ptr = (QNodePtr)malloc(sizeof(QNode));
    if (!ptr)
        return ERROR;
    ptr->data = e;
    ptr->next = NULL;

    Q->rear->next = ptr; //把新结点ptr赋值给原队尾结点的后继
    Q->rear = ptr;       //把新结点ptr设置为队尾结点

    return OK;
}


Status DeLinkQueue(LinkQueue *Q, ElemType *e)
{
    if (Q->front == Q->rear)
        return ERROR;
    QNodePtr ptr = Q->front->next;
    *e = ptr->data;

    Q->front->next = ptr->next;
    if (ptr == Q->rear)
        Q->rear = Q->front;

    free(ptr);
    return OK;
}

Status ClearLinkQueue(LinkQueue *Q)
{
    if (Q->front == Q->rear)
        return OK;

    Q->rear = Q->front;
    QNodePtr p, q;
    p = Q->front->next;
    Q->front->next = NULL;

    while (p)
    {
        q = p;
        p = p->next;
        free(q);
    }

    return OK;
}

Status DestroyLinkQueue(LinkQueue *Q)
{
    while (Q->front)
    {
        Q->rear = Q->front->next;
        free(Q->front);
        Q->front = Q->rear;
    }
    return OK;
}

Status GetLinkHead(LinkQueue *Q, ElemType *e)
{
    if (Q->front == Q->rear)
        return ERROR;

    *e = Q->front->next->data;
    return OK;
}

Status LinkQueueTraverse(LinkQueue Q)
{
    QNodePtr ptr = Q.front->next;
    while (ptr)
    {
        visit(ptr->data);
        ptr = ptr->next;
    }

    return OK;
}

void LinkQueueStart()
{
    LinkQueue Q;

    if (OK == InitLinkQueue(&Q))
        printf("
链队列初始化完成
");

    if (LinkQueueEmpty(Q))
        printf("
链队列为空!
");
    else
        printf("
链队列不为空，队列长度: %d
", GetLinkQueueLegth(Q));

    for (int i = 1; i <= 5; ++i)
        EnLinkQueue(&Q, i);

    printf("
入队 1-5 后的队列长度: %d
", GetLinkQueueLegth(Q));

    LinkQueueTraverse(Q);

    if (LinkQueueEmpty(Q))
        printf("

链队列为空!
");
    else
        printf("
链队列不为空，队列长度: %d
", GetLinkQueueLegth(Q));

    ElemType e;
    GetLinkHead(&Q, &e);
    printf("
对头元素为: %d
", e);

    DeLinkQueue(&Q, &e);
    printf("
对头出列: %d
", e);

    printf("
对头出列后的队列长度: %d
", GetLinkQueueLegth(Q));

    ClearLinkQueue(&Q);
    printf("
清空列后的队列长度: %d
", GetLinkQueueLegth(Q));

    DestroyLinkQueue(&Q);
    printf("
销毁队列后,Q.front= %u Q.rear= %u
", Q.front, Q.rear);

}

main.c:

int main()
{
    //LinkListStart();
    //StackStart();
    //LinkStackStart();
    //StartQueue();
    LinkQueueStart();
    getchar();
    return 0;
}