Question 4: A Perl solution 

#!/usr/bin/perl

$posx = 0;
$posy = 511;
$minx = 0;
$maxx = 0;
$miny = 0;
$maxy = 0;
$next = 0;

while (<>) {
    @chars = split //;
    foreach (@chars) {
        if ($_ eq 'N') {$posy += 1};
        if ($_ eq 'S') {$posy -= 1};
        if ($_ eq 'W') {$posx -= 1};
        if ($_ eq 'E') {$posx += 1};
        if ($_ eq '*') {
            $image[$posx][$posy] = 1;
        }
        else {
            $image[$posx][$posy] = 0;
        }
        $posx > $maxx and $maxx = $posx;
        $posx < $minx and $minx = $posx;
        $posy > $maxy and $maxy = $posy;
        $posy < $miny and $miny = $posy;
    }
}
$maxx++;
$maxy++;

print "P1 $maxx $maxy\n";
for ($i=0; $i<$maxx; $i++) {
    for ($j=0; $j<$maxy; $j++) {
        print $image[$i][$j];
    }
    print "\n";
}

• Output