2022 Advent Stacks

gistfile1.txt

<?php
$fp = fopen('input.txt', 'r');
$data = [];
$cmds = [];
while (($line = fgets($fp, 64)) !== false) {
    if (strpos($line, '[') !== false) {
        $data[] = str_split($line);
    } elseif (strpos($line, 'move') !== false) {
        preg_match('/move (\d+) from (\d+) to (\d+)/', $line, $matches);
        $cmds[] = $matches;
    }
}
$stacks = [];
for ($i = 0; $i < sizeof($data[0]) / 4; $i++) {
   $stacks[] = trim(strrev(implode('', array_column($data, $i * 4 + 1))));
}
foreach ($cmds as $cmd) {
    $stacks[$cmd[3] - 1] .= strrev(substr($stacks[$cmd[2] - 1], $cmd[1] * -1));
    $stacks[$cmd[2] - 1] = substr($stacks[$cmd[2] - 1], 0, $cmd[1] * -1);
}
$output = '';
foreach ($stacks as $stack) {
    $output .= substr($stack, -1);
}
echo "$output\n";

Praktikas saaks selle koodijupi veel umbes poole lühemaks optimeerida. Esiteks on sisendafail alati üks, mis võimaldab osa asju hardcodeda ning teiseks on korralduste ajaks andmed juba olemas ning nende protsessimine võiks toimuda koos lugemisega. Pluss paar nipet-näpet asja veel.