数据结构，循环队列各功能的实现

#include<stdio.h>

#include<malloc.h>

#define MAXLEN 100

typedef struct{

    int data[MAXLEN];

    int front,rear;

}csequeue;

void emptyqueue(csequeue *q)

{

    q->front=q->rear=MAXLEN-99;

}

void Inqueue(csequeue *q)

{

    int x;

    printf("\t\t请输入要进队的整数，以数字0结束！！！\n");

    while(1)

    {

        scanf("%d",&x);

        if(q->front==(q->rear+1)%MAXLEN)

        {

            printf("\t\t队列已满，无法进队\n");

            return ;

        }

        else if(x==0)

            break;

        else

        {

            q->rear=(q->rear+1)%MAXLEN;

            q->data[q->rear]=x;

        }

    }

    printf("\t\t进队成功\n");

}

void Outqueue(csequeue *q)

{

    if(q->front==q->rear)

    {

        printf("\t\t队列为空，无法出队\n");

        return ;

    }

    else

    {

        q->front=(q->front+1)%MAXLEN;

        printf("\t\t输出队首元素\n");

        printf("%d\n",q->data[q->front]);

    }

}

void Showqueue(csequeue *q)

{

    int i;

    if(q->rear==q->front)

    {

        printf("\t\t队列为空，请将元素入队\n");

        return ;

    }

    else

    {

        i=q->front;

        printf("\t\t队列中的元素为：\n");

        while(1)

        {

            if(i==q->rear)

                break;

            else

            {

                i=(i+1)%MAXLEN;

                printf("%d ",q->data[i]);

            }

        }

    }

}

void Lenthqueue(csequeue *q)

{

    int len;

    len=(q->rear-q->front+MAXLEN)%MAXLEN;

    printf("\t\t%d\n",len);

}

int main ()

{

    int m;

    csequeue q;

    emptyqueue(&q);

    printf("\t\t\t     ----循环队列----\n\n");

    while(1)

    {

        printf("\n\t\t*******************************************\n");

        printf("\t\t*                  指令说明               *\n");

        printf("\t\t*               1:进      队              *\n");

        printf("\t\t*               2:出      队              *\n");

        printf("\t\t*               3:显      示              *\n");

        printf("\t\t*               4:求队列长度              *\n");

        printf("\t\t*               0:返      回              *\n");

        printf("\t\t*******************************************\n\n");

        printf("\t请输入指令：");

        scanf("%d",&m);

        if(m==1)

            Inqueue(&q);

        else if(m==2)

            Outqueue(&q);

        else if(m==3)

            Showqueue(&q);

        else if(m==4)

            Lenthqueue(&q);

        else if(m==0)

            return 0;

        else

            printf("输入数据错误，请重新输入！！！\n");

    }

    return 0;

}