UNSW ProgComp: Problem 1 - 2007

<?php

$input = <<<END
4
0509
1685
2933
2259
END;

$input = explode("\n", $input);
array_shift($input); //scrap the first line

foreach($input as $line){
    $line2 = str_split($line);
    $hour = $line2[0].$line2[1];
    $minute = $line2[2].$line2[3];
    $break = false;
    if($minute > 59 || $hour > 23){
        echo str_pad($line, 7)."Invalid time\n";
        $break = true;
    }
    if($hour > 11){
        $append = ' PM';
    }else{
        $append = ' AM';
    }
    if($hour > 12){
        $hour -= 12;
    }
    if($break == false){
        echo str_pad($line, 7).str_pad(intval($hour), 2, ' ', STR_PAD_LEFT).':'.$minute.$append."\n";
    }
}