code-diesel

<?php
 
function getDeck($n)
{
    if (!is_int($n) || $n < 1) {
        throw new DomainException('Number of decks must be positive integer.');
    }
 
    return array_combine(
        range(0, 10),
        array_fill(0, 11, 4 * $n)
    );
}
 
function numDigits($decks, $piFile, $bufferSize = 20)
{
    $deck = getDeck($decks);
    if (!file_exists($piFile)) {
        throw new InvalidArgumentException('Pi file does not exist.');
    }
    if (!is_int($bufferSize) || $bufferSize < 1) {
        throw new DomainException('Buffer size must be positive integer.');
    }
 
    $fp = fopen('pi.txt', 'r');
    $count = 0;
    while (!feof($fp)) {
        $buffer = fread($fp, $bufferSize);
        for ($i = 0, $s = strlen($buffer); $i < $s; ++$i) {
            $d = $buffer[$i];
            if (!preg_match('#[0-9]#s', $d)) {
                continue;
            }
 
            if ($deck[$d] === 0) {
                break 2;
            }
 
            ++$count;
            --$deck[$d];
        }
    }
    fclose($fp);
 
    $foundZero = false;
    foreach ($deck as $n) {
        if ($n === 0) {
            $foundZero = true;
        }
    }
 
    if (!$foundZero) {
        throw new RuntimeException('Ran out of digits.');
    }
 
    return $count;
}
 
try {
    if ($argc !== 3) {
        throw new InvalidArgumentException(sprintf('Usage: %s numDecks piFile', $argv[0]));
    }
 
    $decks = (int) $argv[1];
    $piFile = $argv[2];
 
    printf('Using %d deck(s) you can get %d digits of pi' . PHP_EOL, $decks, numDigits($decks, $piFile));
}
catch (Exception $e) {
    fprintf(STDERR, $e->getMessage() . PHP_EOL);
    exit(1);
}
?>

/**
 * @author marcin@php4u.co.uk
 */
 
puzzle2solver::solve(1);
 
class puzzle2solver {
 
    /**
     * Gets first $precision numbers of pi
     * @param int $precision
     */	
    public static function getPiNumbers($precision) {
        echo "Getting PI...";
        $pi_numbers = substr(preg_replace('/[^0-9]/','', strip_tags(file_get_contents('http://www.exploratorium.edu/pi/Pi10-6.html', FILE_TEXT))),0,$precision);
        echo "Ok\n";
        return $pi_numbers;
    }
 
    /**
     * Solver
     *
     * @param int $decks
     */
    public static function solve($decks) {
        if (is_int($decks) && $decks > 0) {
            $length = $decks * 40; // this is maximum what we can get 
            $pi_numbers = self::getPiNumbers($length); // take our pi numbers
 
            $starttime = microtime(true);
            $deck = new deck($decks); // initiate deck object
            $n=0;
            while ($n<$length) {
                if (!$deck->takeCard($pi_numbers[$n])) { // take our number from the stock
                    break; // if failed we don't have more cards
                }
                $result .= $pi_numbers[$n];
                $n++; // take next number
            }
            $time = microtime(true)-$starttime;
            echo "Solution: {$result} [{$n} numbers]\n";
            echo "Time: ".sprintf("%2.10f",$time)." secs\n";
        } else {
            echo "usage: php ".__file__." number_of_decks\n";	
        }
    }
}
 
/**
 * Class which represents our decks
 */
class deck {
 
    /**
     * How many decks we have
     *
     * @param int $decks_number
     */
    public function __construct($decks_number) {
        $this->decks_number = $decks_number * 4; // 4 cards from each deck
        $this->decks = array_fill(0, 10, 0);
    }
 
    /**
     * Takes card (we increase our card counter), returns false if we ran out of cards
     *
     * @param int $number [0-9]
     * @return boolean
     */
    public function takeCard($number) {
        if ($this->decks[$number]==$this->decks_number) {
            return false; 
        } else {
            $this->decks[$number]++;
            return true;
        }
    }
}