<?php

require 'vendor/autoload.php';

class QueueNode

{

function QueueNode($data)

{

$this->data = $data;

$this->next_node = NULL;

}

}

class Queue

{

function Queue()

{

$this->front = NULL;

$this->back = NULL;

}

function is_empty()

{

return $this->front == NULL;

}

function push_back($item)

{

if (!$this->front)

{

$this->back = new QueueNode($item);

$this->front = $this->back;

}

else

{

$this->back->next_node = new QueueNode($item);

$this->back = $this->back->next_node;

}

}

function pop_front()

{

$result = $this->front->data;

$this->front = $this->front->next_node;

return $result;

}

}

class QueueTest extends PHPUnit_Framework_TestCase

{

public function testEverything()

{

$queue = new Queue();

$this->assertTrue($queue->is_empty());

$queue->push_back(1);

$queue->push_back(2);

$queue->push_back(3);

$this->assertFalse($queue->is_empty());

$this->assertEquals(1, $queue->pop_front());

$this->assertEquals(2, $queue->pop_front());

$this->assertEquals(3, $queue->pop_front());

$this->assertTrue($queue->is_empty());

$queue->push_back(4);

$this->assertFalse($queue->is_empty());

$this->assertEquals(4, $queue->pop_front());

$in_cnt = 0;

$out_cnt = 0;

for ($i = 1; $i < 50; $i++)

{

for ($j = 0; $j < $i; $j++)

{

$queue->push_back($in_cnt);

$in_cnt++;

}

$this->assertEquals($out_cnt, $queue->pop_front());

$out_cnt++;

}

while (!$queue->is_empty())

{

$this->assertEquals($out_cnt, $queue->pop_front());

$out_cnt++;

}

}

}

$suite = new PHPUnit_Framework_TestSuite();

$suite->addTestSuite('QueueTest');

PHPUnit_TextUI_TestRunner::run($suite);

?>