Turing Machine NEW

<?php
//Enter your code here, enjoy!

$alphabet = '';
$carets = '';

$EMPTY_SYMBOL = '';
$STOP_CARET_SYMBOL = '';

$str_cassette = '';

$position = 0;

$table = [];

$temp_to_write = '';

//Ввод данных

getConsoleData('Write a alphabet of Turing Machine', $alphabet);
$alphabet = explode(' ', $alphabet);

getConsoleData('Write a list of carets', $carets);
$carets = explode(' ', $carets);

getConsoleData('Write a empty symbol', $EMPTY_SYMBOL);
$alphabet = array_merge([$EMPTY_SYMBOL], $alphabet);

getConsoleData('Write a stop carets symbol', $STOP_CARET_SYMBOL);


getConsoleData('Write a default cassette', $str_cassette);

getConsoleData('Write a position on cassette', $position);

foreach ($carets as $key => $caret) {
    foreach ($alphabet as $value) {
        getConsoleData('Write ' . $caret . '->' . $value, $temp_to_write);
        $table[$caret][$value] = explode(' ', $temp_to_write);
    }
}

//print_r($table);

//Конец ввода данных

//Выполнение алгоритма
$explode_cassette = explode(' ', $str_cassette);
$cassette = array_merge([$EMPTY_SYMBOL], $explode_cassette , [$EMPTY_SYMBOL]);

/*print_r($cassette);*/
$position = count($explode_cassette);
/*$table = [
    'q1' => ['', ['q2', $EMPTY_SYMBOL, 'l'], ['q0', $EMPTY_SYMBOL, 's']],//['q3', '1', 'r'], ['q1', $EMPTY_SYMBOL, 'l']
    'q2' => [['q3', '1', 'r'], ['q2', '1', 'l'], ['q2', '*', 'l']],
    'q3' => [['q1', $EMPTY_SYMBOL, 'l'], ['q3', '1', 'r'], ['q3', '*', 'r']]
];*/

$q = 'q1';

$count_iter = 0;
//echo $cassette[$position] . ' ' . $q . PHP_EOL;

//print_r($table[$q][$cassette[$position]]);

while($q != $STOP_CARET_SYMBOL) {
    if($count_iter > 500)
        break;
    $count_iter++;
/*    echo $q . PHP_EOL;
    echo toRow($cassette[$position]) . PHP_EOL;
    exit();*/
    $current = $table[$q][$cassette[$position]];
    $temp_q = $q;
    $temp_cassette = $cassette[$position];
    $cassette[$position] = $current[1];
    $q = $current[0];
    if($current[2] == 'l') {
        $position--;
    }elseif($current[2] == 'r') {
        $position++;
    }
    if($position < 0) {
        $cassette = array_merge([$EMPTY_SYMBOL], $cassette);
        $position = 0;
    }
    if($position > count($cassette))
        $cassette = array_merge( $cassette, [$EMPTY_SYMBOL]);
    echo $count_iter . ') ' . $temp_q . $temp_cassette . '->' . implode('', $current) . PHP_EOL;
    $line = str_create('-', count($cassette)*2+1) . PHP_EOL;
    echo $line;
    echo '|' . implode('|', $cassette) . '|' . PHP_EOL;
    echo $line;
}

/*function toRow($name) {
    $rows = [$EMPTY_SYMBOL => 0, '1' => 1, '*' => 2];
    return $rows[$name];
}*/

function str_create($symbol, $count) {
    if($count < 2) return $symbol;
    return $symbol . str_create($symbol, $count - 1);
}

function getConsoleData($message, &$var) {
    echo $message . ': ';
    $var = trim(fgets(STDIN));
    echo PHP_EOL;
}