<?php

$lines = array_filter(explode("\n", file_get_contents(__DIR__.'/input.txt')), static fn($line) =>!empty($line));

$count = 0;
$position = 50;

echo 'The dial starts by pointing at 50'."\n";

function checkPosition(&$position)
{
    if ($position < 0) {
        $position = 100 - abs($position);
    } elseif ($position > 99) {
        $position = $position - 100;
    }
}

foreach ($lines as $line) {
    $direction = substr($line, 0, 1);
    $number = (int)substr($line, 1) % 100;
    if ($direction === 'L') {
        $position -= $number;
        checkPosition($position);
    } elseif ($direction === 'R') {
        $position += $number;
        checkPosition($position);
    }

    if ($position === 0) {
        $count++;
    }

    echo sprintf('The dial is rotated %s to point at %u | count : %u%s', $line,$position, $count, "\n");
}