haiku_perl.pl

use strict;
use warnings;
use utf8;
binmode(STDOUT, ":utf8");

my($i,$j,$word);
my(@s) = reverse(split(/,/,"古池や,蛙飛びこむ,水の音"));

print process(0,@s);

sub process {
    my($index) = shift; my($w,$v) = ""; my($k) = 0; my($result) = ""; my(@vert);
    foreach $w (@_) { if ($k < length($w)) { $k = length($w); } } if ($index > $k) { return ""; }
    foreach $w (@_) {
        $k=0; $v=""; @vert = (split(//,$w));
        if (scalar(@vert) > $index) { $result .= $vert[$index]; } else { $result .= "　";  }
    }
    return $result . "\n" . &process($index+1,@_) 
}