<?php
/**
* php模拟循环队列
* Class myQueue
*/
class myQueue
{
public $arr = []; // int类型 队列数组
public $front; // 队头索引
public $rear; // 队尾索引
public $count = 0; //数组现在长度
public $max; //数组最大长度
/**
* 构造器
* myQueue constructor.
* @param int $num
*/
public function __construct(int $num)
{
$this->max = $num; //数组最大长度
$this->front = $num; // 队列头下标
$this->rear = $num; // 队列尾下标
}
/**
* 入队列
* @param int $element
* @throws Exception
*/
public function in(int $element)
{
// 判断长度是否超出
if ($this->count == $this->max) throw new Exception("长度溢出");
$this->rear = ($this->rear + 1) % $this->max;
$this->arr[$this->rear] = $element;
$this->count++;
}
/**
* 出队
* @return mixed
* @throws Exception
*/
public function out(): int
{
if ($this->count == 0) throw new Exception("队列空了!");
$this->front = ($this->front + 1) % $this->max;
$element = $this->arr[$this->front];
unset($this->arr[$this->front]);
$this->count--;
return $element;
}
}
try {
$queue = new myQueue(10);
$queue->in(10);
$queue->in(20);
$queue->out();
echo '<pre>';
print_r($queue);
} catch (Exception $exception) {
echo $exception->getMessage();
}
