Rally Software Coding Exercise by Dan Mandle

pokerhand.php

<?php

/*

NOTE: This is designed to be run from the terminal.

------------
-Exercise 2-
------------
Write some code that will evaluate a poker hand and determine its rank.

*/

class pokerRound{

	public $deck;

	function __construct(){
		$this->shuffleDeck();
	}

	public function shuffleDeck(){
		// populate deck
		$suits = array('h', 's', 'd', 'c');
		$values = array_merge(range(2, 10), array('J','Q','K','A'));

		foreach($suits as $suit){
			foreach($values as $value){
				$this->deck[] = $value.$suit;
			}
		}

		shuffle($this->deck);

		return $this->deck;
	}

	public function dealHands($num_players = 1){

		if(sizeof($this->deck) < 5){
			echo "Too many players, not enough cards left.";
			exit;
		}

		// in order to properly deal, each player has to get one card, then two cards, etc.
		$hands = array();
		while(sizeof($hands[$num_players]) < 5){ // while the last hand has less than 5 cards
			for($player=1; $player <= $num_players; $player++){
				$hands[$player][] = array_shift($this->deck); // grab a card from the front of the array
			}
		}

		return $hands;
	}

	public function evaluateHand($cards){
		$hand = array();
		foreach($cards as $card){

			$suit = substr($card, -1); // last char is suit
			$card = substr($card, 0, -1); // everything that's not the suit is the value

			empty($hand['suits'][$suit]) ? $hand['suits'][$suit] = 0 : NULL; // squash PHP notices
			$hand['suits'][$suit] += 1;

			switch($card){
				case 'J':
					$card = 11;
					break;
				case 'Q':
					$card = 12;
					break;
				case 'K':
					$card = 13;
					break;
				case 'A':
					$card = 14;
					break;
			}

			empty($hand['values'][$card]) ? $hand['values'][$card] = 0 : NULL; // squash PHP notices
			$hand['values'][$card] += 1;
		}

		ksort($hand['values']);
		$values = array_keys($hand['values']);

		$of_a_kind = max($hand['values']);

		if($of_a_kind == 1){
			$straight = true;
			for($i=0; $i < sizeof($values)-1; $i++){
				if($values[$i]+1 != $values[$i+1]){
					$straight = false;
					break;
				}
			}
		}
		else{
			$straight = false;
		}

		// $flush = max($hand['suits']) == 5 ? true : false;
		$flush = sizeof($hand['suits']) == 1 ? true : false;

		if($straight && $flush){
			// Straight Flush
			return 'sf';
		}
		elseif($of_a_kind == 4){
			// Four of a Kind
			return '4ok';
		}
		elseif($of_a_kind == 3 && in_array(2, $hand['values'])){
			// full house
			return 'fh';
		}
		elseif($flush){
			// yup, flush
			return 'fl';
		}
		elseif($straight){
			// straight
			return 'st';
		}
		elseif($of_a_kind == 3){
			// three of a kind
			return '3ok';
		}
		elseif(sizeof(array_keys($values, 2)) == 2){
			// two pairs
			return '2p';
		}
		elseif($of_a_kind == 2){
			// Pair
			return '2ok';
		}
		else{
			// High Card
			return 'hc';
		}
	}

	public function printHandValue($hand_code){
		switch($hand_code){
			case 'sf':
				echo PHP_EOL."Straight Flush! Top Hand!".PHP_EOL;
				break;
			case '4ok':
				echo PHP_EOL."Four of a Kind. Second best hand!".PHP_EOL;
				break;
			case 'fh':
				echo PHP_EOL."Full House! Third best hand".PHP_EOL;
				break;
			case 'fl':
				echo PHP_EOL."Flush! Fourth best.".PHP_EOL;
				break;
			case 'st':
				echo PHP_EOL."Straight".PHP_EOL;
				break;
			case '3ok':
				echo PHP_EOL."Three of a kind".PHP_EOL;
				break;
			case '2p':
				echo PHP_EOL."Two Pair".PHP_EOL;
				break;
			case '2ok':
				echo PHP_EOL."Pair".PHP_EOL;
				break;
			case 'hc':
				echo PHP_EOL."High Card. Better luck next time...".PHP_EOL;
				break;
		}
	}
}

$pokerRound = new pokerRound();

$hands = $pokerRound->dealHands(5);

foreach($hands as $hand){
	for($i=0; $i<5; $i++){
		echo $hand[$i];
		$i<4 ? print(",") : print(PHP_EOL);
	}
	$pokerRound->printHandValue($pokerRound->evaluateHand($hand));

	echo PHP_EOL.'======================='.PHP_EOL;
}