数据结构 --- 循环队列（队列的顺序存储结构）

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.h:

#include "common.h"

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

Queue.h:

//循环队列的结构
typedef struct
{
    ElemType data[MAXSIZE];
    int front;                //头指针
    int rear;                //尾指针，队列不为空，指向队列尾元素的下一位
}SqQueue;

Queue.c:

#include <stdio.h>
#include "common.h"
#include "Queue.h"

Status InitQueue(SqQueue *Q)
{
    Q->front = 0;
    Q->rear = 0;
    return OK;
}

Status ClearQueue(SqQueue *Q)
{
    Q->front = Q->rear = 0;
    return OK;
}

Status QueueEmpty(SqQueue Q)
{
    if (Q.front == Q.rear)
        return OK;
    else
        return FALSE;
}

int GetQueueLength(SqQueue Q)
{
    return (Q.rear - Q.front + MAXSIZE) % MAXSIZE;
}

Status EnQueue(SqQueue *Q, ElemType e)
{
    //队列已满
    if ((Q->rear + 1) % MAXSIZE == Q->front)
        return FALSE;

    Q->data[Q->rear] = e;
    Q->rear = (Q->rear + 1) % MAXSIZE; //队尾向后以一个元素，队满后则转移到队列头部
    return OK;
}

Status DeQueue(SqQueue *Q, ElemType *e)
{
    if (Q->front == Q->rear)   //队列为空
        return FALSE;

    *e = Q->data[Q->front];
    Q->front = (Q->front + 1) % MAXSIZE;

    return OK;
}

Status GetQueueHead(SqQueue *Q, ElemType *e)
{
    if (Q->front == Q->rear) //队列为空
        return FALSE;
    *e = Q->data[Q->front];
    return OK;
}

Status QueueTraverse(SqQueue Q)
{
    int index = Q.front;
    while ((index + Q.front) != Q.rear)  //遍历完成
    {
        visit(Q.data[index]);
        index = (index + 1) % MAXSIZE;
    }

    return OK;
}

void StartQueue()
{
    SqQueue Q;
    if (OK == InitQueue(&Q))
        printf("
循环队列初始化成功!
");

    for (int i = 1; i <= 10; ++i)
        EnQueue(&Q, i * 2);

    printf("

插入数据1-10后的队列长度为: %d
", GetQueueLength(Q));

    printf("

队列中的元素是:
");
    QueueTraverse(Q);

    int e;
    DeQueue(&Q, &e);
    printf("

队首出列: %d
", e);
    printf("

队首出列后的队列长度为: %d
", GetQueueLength(Q));

    GetQueueHead(&Q, &e);
    printf("

队首元素为: %d
", e);

    ClearQueue(&Q);
    printf("

清空后的队列长度: %d
", GetQueueLength(Q));
}

main.c:

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