PHP look_and_say Examples

Example #1

File: part2.php Project: navarr/advent-of-code

<?php

require_once 'inc/look_and_say.func.php';
// ridiculously high.
ini_set('memory_limit', '1G');
$result = trim(file_get_contents('input.txt'));
for ($i = 0; $i < 50; ++$i) {
    $result = look_and_say($result);
}
$len = strlen($result);
echo "Answer: {$len}\n";

Example #2

File: advofcode_10_1.php Project: nicuserban/adventofcode

<?php

$input_str = '1321131112';
$turns_nr = 40;
echo '<pre>';
var_dump(look_and_say($input_str, $turns_nr));
echo '</pre>';
function look_and_say($str, $turns_nr)
{
    for ($i = 0; $i < $turns_nr; $i++) {
        $length = strlen($str);
        $new_str = '';
        $current_char_nr = 0;
        $current_char = '';
        for ($j = 0; $j < $length; $j++) {
            $char = $str[$j];
            if (empty($current_char) || $current_char != $char) {
                if (!empty($current_char) && !empty($current_char_nr)) {
                    $new_str .= $current_char_nr . $current_char;
                }
                $current_char = $char;
                $current_char_nr = 0;
            }
            $current_char_nr++;
            $chars[$char] = true;
        }
        $new_str .= $current_char_nr . $current_char;
        $str = $new_str;
    }
    return strlen($str);
}