Simple Spies Program

detektif.php

<?php

/**
 * Program interogasi sederhana
 *
 * @author Taufan Aditya <[email protected]>
 */

class Node {
	public $question;
	public $yes;
	public $no;

	/**
	 * Node factory
	 *
	 * @param string Pertanyaan
	 * @return Node
	 */
	public static function create($question = '')
	{
		$node = new static();
		$node->question = $question;
		$node->yes = NULL;
		$node->no = NULL;

		return $node;
	}
}

class Interogation {

	/**
	 * Ambil argument dari standard input
	 *
	 * @param int Limit karakter
	 */
	public function get_stream($limit = 0)
	{
		$stdin = fopen('php://stdin','r');
		$stream = trim(fgets($stdin, $limit), "\n");
		fclose($stdin);

		return $stream;
	}

	/**
	 * Ajukan pertanyaan
	 *
	 * @param string Pertanyaan
	 * @return bool Jawaban (TRUE = Yes, FALSE = No)
	 */
	public function yes_no($question = '')
	{
		if (empty($question)) {
			return FALSE;
		}

		printf("%s? (y/n)", $question);
		$answer = $this->get_stream(3);

		return strtolower(substr($answer,0,1)) == 'y';
	}

	/**
	 * Main function
	 */
	public function start()
	{
		$start = Node::create('Apakah dia laki-laki');
		$start->yes = Node::create('Arliansah');
		$start->no = Node::create('Youppie');

		do {
			$current = $start;
			while(true) {
				if ($this->yes_no($current->question)) {
					if ($current->yes) {
						$current = $current->yes;
					} else {
						printf("Tersangka ditemukan! %s!\n", $current->question);
						break;
					}
				} elseif ($current->no) {
					$current = $current->no;
				} else {
					/* Buat target baru */
					printf("Kalau begitu siapa namanya?");
					$suspect = $this->get_stream(20);

					/* Buat kopi target */
					$current->yes = Node::create($suspect);
					$current->no = Node::create($current->question);

					/* Dan ganti pertanyaan ini dengan pertanyaan baru */
					printf("Berikan pertanyaan yang YES untuk %s tapi NO untuk %s?\n", 
					       $suspect, 
					       $current->question);

					$question = $this->get_stream(40);
					$current->question = $question;

					break;
				}
			}
		} while ($this->yes_no('Ulang kembali'));
	}
}

$app = new Interogation();
$app->start();