5_24_打卡_数据结构之循环队列

//循环队列可存储数据数量是maxsize-1
//队列长度为（front-rear+maxsize）%maxsize
//队列为空时front==rear
//队列满时 （front+1）%maxsize==rear；

#define MAXSIZE 5
#include<iostream>
using namespace std;

typedef struct queue {
	int front;
	int rear;
	int data[MAXSIZE];
}queue;

queue* initqueue()
{
	queue* q = new queue;
	q->rear = 0;
	q->front = 0;
	return q;
}

bool isfull(queue* q)
{
	if ((q->front + 1) % MAXSIZE == q->rear)
	{
		return true;
	}
	else
		return false;
}

void push(queue* q,int data)
{
	if (isfull(q))
	{
		return;
	}
	else {
		q->data[q->front] = data;
		q->front = (q->front + 1) % MAXSIZE;
	}
}


bool isempty(queue* q)
{
	if (q->front == q->rear)
	{
		return true;
	}
	else
		return false;
}

int pop(queue* q)
{
	if (isempty(q))
	{
		return -1;
	}
	else {
		int data = q->data[q->rear];
		q->rear = (q->rear + 1) % MAXSIZE;
		return data;
	}
}

void print(queue* q)
{
	int len = (q->front - q->rear + MAXSIZE) % MAXSIZE;
	int index = q->rear;
	for (int i = 0; i < len; i++)
	{
		cout << q->data[index] << "->";
		index = (index + 1) % MAXSIZE;
	}
	cout << "NULL" << endl;
}

int main()
{
	queue* q = initqueue();
	push(q, 1);
	push(q, 2);
	push(q, 3);
	push(q, 4);
	push(q, 5);
	push(q, 6);
	push(q, 7);
	print(q);
	int i = pop(q);
	pop(q);
	print(q);

	return 0;
}