循环队列

#include<iostream>
#define maxsize 1000
using namespace std;
typedef struct {
    int *base;
    int front;
    int rear;
}SqQueue;
void InitQueue(SqQueue &q)
{
    q.base = new int[maxsize];
    if (!q.base)
        return;
    q.front = q.rear = 0;
}
int QueueLength(SqQueue q)
{
    return (q.rear - q.front + maxsize) % maxsize;
}
void EnQueue(SqQueue &q,int e)
{
    if ((q.rear + 1) % maxsize == q.front)
    {
        return;
    }
    q.base[q.rear] = e;
    q.rear = (q.rear + 1) % maxsize;
}
void DeQueue(SqQueue &q, int e)
{
    if (q.front == q.rear)
        return;
    e = q.base[q.front];
    q.front = (q.front + 1) % maxsize;
}