循环队列的初始化

#include <stdio.h>
#include <stdlib.h>

#define MAXSIZE 3
#define INCREASESIZE 3

typedef struct SqListQueeu
{
    int *elem;
    int front;
    int rear;
    int maxsize;
    int increasesize;
}SqQueue;

 
bool Init(SqQueue &Q)//初始化队列
{
    Q.elem = (int *)malloc(MAXSIZE * sizeof(int));//18
    Q.maxsize = MAXSIZE;
    Q.increasesize = INCREASESIZE;
    Q.front = Q.rear = 0;
}

void increase(SqQueue &Q)//进队列
{
    Q.elem = (int *)realloc(Q.elem, (Q.maxsize + Q.increasesize) * sizeof(int));
    Q.maxsize += Q.increasesize;
}

void EnQueue(SqQueue &Q, int e)//入队列
{
    if (Q.front == (Q.rear + 1) % Q.maxsize)
        increase(Q);
    Q.elem[Q.rear] = e;
    Q.rear = (Q.rear + 1) % Q.maxsize;
}
bool is_empty(SqQueue Q)//判空
{
    if (Q.front == Q.rear)
        return true;
    else
        return false;
}

int length(SqQueue Q)//求队列的长度
{
    return (Q.rear - Q.front + Q.maxsize) % Q.maxsize;
}

 
bool DeQueue(SqQueue &Q, int &e)//出队列
{
    if (is_empty(Q))
    {
        printf("Queue is empty! ^_^ \n");
        e = 0;
        return false;
    }
    e = Q.elem[Q.front];
    Q.front = (Q.front + 1) % Q.maxsize;
    return true;
}

bool print(SqQueue Q)//输出元素
{
    int e;
    while (!is_empty(Q))
    {
        DeQueue(Q, e);
        printf("%d  ", e);
    }
    printf("\b\b \n");
}

int main()
{
    SqQueue Q;
   
    Init(Q);
    EnQueue(Q, 0);
    EnQueue(Q, 1);
    EnQueue(Q, 2);
    EnQueue(Q, 3);
    EnQueue(Q, 4);
    EnQueue(Q, 5);
    EnQueue(Q, 6);
    EnQueue(Q, 7);
    EnQueue(Q, 8);
    EnQueue(Q, 9);
    printf("LENGTH = %d\n", length(Q));
    print(Q);
   
    return 0;
}