UNSW ProgComp: Problem 1 - 2008

<?php

$input = <<<END
10
10 750
1.8 0
3.5 0
10 0
10 71.428571428571428571428571428571
5.5 1000
10 1220
16.5 500
22 600
26 1000
END;

$input = explode("\n", $input);
array_shift($input);

foreach($input as $key => $value){
    $input[$key] = explode(" ", $value);
}
//distance km, ascention m

function roundnum($num, $nearest = 5){
    return round($num / $nearest) * $nearest;
}

function rule_times($d, $a){
    $time1 = $d/3.5 + $a/500;
    if($time1 > 3){
        $time2 = 0.02*pow($time1, 2) + 1.19*$time1 - 0.75;
    }else{
        $time2 = $time1;
    }

    //round to the nearest 5
    $time1_min = str_pad(roundnum(($time1 - floor($time1))*60), 2, '0', STR_PAD_LEFT);
    $time2_min = str_pad(roundnum(($time2 - floor($time2))*60), 2, '0', STR_PAD_LEFT);

    $time1 = floor($time1).':'.$time1_min;
    $time2 = floor($time2).':'.$time2_min;

    return array($time1, $time2);
}

foreach($input as $key => $value){
    $times = rule_times($value[0], $value[1]);
    $d = str_pad(number_format($value[0], 1, '.', '').'km', 7, ' ', STR_PAD_LEFT);
    $a = str_pad(number_format($value[1], 0, '.', '').'m', 7, ' ', STR_PAD_LEFT);
    $n_time = str_pad($times[0], 6, ' ', STR_PAD_LEFT);
    $a_time = str_pad($times[1], 6, ' ', STR_PAD_LEFT);

    echo 'Distance:'.$d.'  ascent:'.$a.'  Naismith:'.$n_time.'  adjusted time:'.$a_time."\n";
}