循环队列实现

#define MAX_SIZE 1000
int que_length = 0;
int que_rear = 0;
int que_front = 0;
struct fifo{
    int data;
}que[MAX_SIZE];

int ()
{
    return que_length;
}

void push(int val)
{
    que[que_rear].data = val;     
    que_length++;
    que_rear = (que_rear + 1) % MAX_SIZE;
}

int pop()
{
    int p;
    p = que[que_front].data;
    que_front = (que_front + 1) % MAX_SIZE;
    que_length--;
    return p;
}

int isempty()
{
    return que_length == 0;
}

int isfull()
{
    return que_length == MAX_SIZE;
}