http://www.perlmonks.org?node_id=487213


in reply to Spiraling integers

A recursive solution:

use strict; use warnings; my $n = shift; my $count = 1; my @matrix; push @matrix, [(0)] for (1..$n); buildRing (0, $n - 1); my $width = length sprintf ("%s", '' . $count); my $format = "%${width}d"; print "" . (join " ", map {sprintf $format, $_} @{$matrix[$_]}) . "\n" + for (0..($n-1)); sub buildRing { my ($first, $last) = @_; $matrix[$first][$_] = $count++ for ($first..$last); $matrix[$_][$last] = $count++ for (($first+1)..$last); $matrix[$last][$last-$_+$first-1] = $count++ for ($first..$last-1); for ($_ = --$last; $_ > $first; --$_) {$matrix[$_][$first] = $count++} $matrix[$first][$last] = $count if (++$first == $last); buildRing ($first, $last) if ($first<$last); }
use strict; use warnings; my $n = shift || 5; my ($count, $first, $last) = (1, 0, $n - 1); my @matrix; push @matrix, [(0)] for (1..$n); { $matrix[$first][$_] = $count++ for ($first..$last); $matrix[$_][$last] = $count++ for (($first+1)..$last); $matrix[$last][$last-$_+$first-1] = $count++ for ($first..$last-1); for ($_ = --$last; $_ > $first; --$_) {$matrix[$_][$first] = $count++} $matrix[$first][$last] = $count if (++$first == $last); redo unless $first >= $last; } my $width = (int log $count) - 1; print "" . (join " ", map {sprintf "%${width}d", $_} @{$matrix[$_]}) . + "\n" for (0..($n-1));
$n=shift;($c,$f,$l,@m)=(1,0,--$n); {$m[$f][$_]=$c++for($f..$l);$m[$_][$l]=$c++for($f+1..$l); $m[$l][$l-$_+$f-1]=$c++for($f..$l-1);for($_=--$l;$_>$f;--$_){$m[$_][$f +]=$c++} $m[$f][$l]=$c if(++$f==$l);redo unless$f>$l}my$w=(int log$c); print"".(join"",map{sprintf"%${w}d",$_}@{$m[$_]})."\n"for(0..$n)
Update: added (smaller) non-recursive version and golf version

Perl is Huffman encoded by design.