queuecricuity.c

练习.................................................

#include "stdio.h"
#include "assert.h"
#include "string.h"

#define QUEUE_LEN       10

#define NULL_PTR          0

int q[QUEUE_LEN] = {0};

/*头*/
int spos = 0;

/*尾部*/
int rpos  = 0;

void queueInit(void)
{
    spos = rpos = 0;
}

int queueEmpty()
{
    return spos == rpos;
}

int queueFull()
{
    return (spos + 1)%QUEUE_LEN == rpos;
}

void queueStore(int data)
{
    if (queueFull())
    {
        printf("\r\nQUEUE FULL");
        return;
    }
    
    q[spos] = data;
    spos = (spos + 1) %QUEUE_LEN;
}

void QueueGetFront(int * pdata)
{
    assert(pdata);
    
    if (queueEmpty())
    {
        printf("\r\nQUEUE NULL");
        return;
    }
    
    *pdata = q[rpos];
    rpos = (rpos + 1 )%QUEUE_LEN;
    
    return;
}

void QueueTraver(void)
{
    int i = rpos;
    while(i != spos)
    {
        printf("\r\nQ DATA[%d]  = %d", i,q[i]);
        i = (i + 1)%QUEUE_LEN;
    }
    return;
}

int main(void)
{
    int i = 0;
    int data = 0;

    for (i = 0; i < QUEUE_LEN; i++)
    {
        queueStore(i);
    }
    
    QueueTraver();
    
    QueueGetFront(&data);
    printf("\r\nGet Data[%d] = %d", rpos - 1,data);


    QueueGetFront(&data);
    printf("\r\nGet Data[%d] = %d", rpos - 1,data);

    queueStore(100);

    queueStore(101);

    queueStore(102);

    QueueTraver();
    return 0;
}