<?php
//$fast = true;
if (isset($fast)) {$fil = "input-fast.txt";echo "Eksempel aktiv\n";} else $fil = "input-full.txt";
$linjer = file($fil, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
 
 
function parse($linje) {
    $step0 = substr($linje,0,7);
    $range = range(0,127);
 
    foreach (str_split($step0) as $char) {
        $step1 = array_chunk($range, count($range)/2, true);
        if ($char == "F") { // Front
            $range = $step1[0];
        } else {
            $range = $step1[1];
        }
    }
    $row = $range;
 
    $step2 = substr($linje,-3);
    $range = range(0,7);
    foreach (str_split($step2) as $char) {
        $step2 = array_chunk($range, count($range)/2, true);
        if ($char == "L") {
            $range = $step2[0];
        } else {
            $range = $step2[1];
        }
    }
    $column = $range;
    return ((array_sum($row) * 8) + array_sum($column));
}
 
$seter = range(0,1000);
foreach ($linjer as $linje) {
    $tall = parse($linje);
    unset($seter[$tall]);
}
 
for ($i=1;$i<=999;$i++) {
    if (isset($seter[$i]) AND !isset($seter[$i-1]) AND !isset($seter[$i+1])) echo "Ditt sete: ".$seter[$i]."\n";
}