UNSW ProgComp: Problem 1 - 2006

<?php
$input = <<<END
1243
1234
1243
1243
1243
1234
1234
1233
1222
1211
1233
1234
1222
1211
1211
1210
-1
END;

$input = explode("\n", $input);
array_pop($input); //remove the negative 1
sort($input); //put elements in order

$max_length = null;

foreach($input as $key => $value){
    $has_dupes = 0;
    foreach($input as $key2 => $value2){
        if($value == $value2 && $key != $key2){
            $has_dupes = 1;
        }
    }
    if(strlen($value) > $max_length){
        $max_length = strlen($value);
    }
    $full_array[$key]['has_dupe'] = $has_dupes;
    $full_array[$key]['val'] = $value;
}

foreach($input as $value){
    echo str_pad($value, $max_length+1, ' ', STR_PAD_RIGHT);
}

echo "\n";

$rank = 0;
$prev = null;
foreach($full_array as $value){
    if($value['val'] != $prev){
        $rank++;
    }
    $prev = $value['val'];
    if($value['has_dupe']){
        echo str_pad($rank.'eq', $max_length+1, ' ', STR_PAD_RIGHT);
    }else{
        echo str_pad($rank, $max_length+1, ' ', STR_PAD_RIGHT);
    }
}