http://qs321.pair.com?node_id=927466

blakew has asked for the wisdom of the Perl Monks concerning the following question:

Bit of silliness.

1. What's the next line?

1
1 1
2 1
1 2 1 1
1 1 1 2 2 1

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2. Write code to print each line in the pattern (it gets unwieldy).

If the 5th line was 3 1 1 2 passing an argument gives that solution- 
my $anchor = @ARGV ? '' : '^';
printf "%d\n", $_ = '1';
do {
    my $new;
    my ( $n ) = /^(\d)/o;
    while ( $_ ) {
        my $c = 0;
        $c++ while s/$anchor\s?$n\s?//;
        $new .= "$c $n " if $c;
        ( $n ) = /^(\d)/o;
    }
    print $_ = $new;
} until ( <STDIN> =~ /\S/ );

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Replies are listed 'Best First'.
Re: What's the answer to this puzzle? Most unique/golfed solution? (fun)
by thundergnat (Deacon) on Sep 23, 2011 at 02:09 UTC

    Hmm. Golf eh? 88 strokes. First 99 19 values. Bleh. 99 takes too long.

    Works under linux, Swap double and single quotes for Windows.

             1         2         3         4         5         6         7         8         9
123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890

    perl -E'$_=1;while(++$t<19){say;my@a;push@a,length$1,$2 while/((\d)\2*
+)/g;$_=join"",@a}'

    [download]

    Update 79 75 73 strokes

             1         2         3         4         5         6         7         8
12345678901234567890123456789012345678901234567890123456789012345678901234567890

    perl -E'for(0..19){say$_=$t//1;$t="";$t.=(length$1).$2 while/((.)\2*)/
+g}'

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[select]
      thundergnat,

      This just trims a few characters from your approach, which I think is a very good one (I couldn't find an inherently better one). 

      # 68 strokes
perl -E'map{say$_=$t||1;$t="";$t.=(length$&).$1while/(.)\1*/g}0..19'

      [download]
      s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/
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Re: What's the answer to this puzzle? Most unique/golfed solution? (fun)
by AnomalousMonk (Archbishop) on Sep 23, 2011 at 01:00 UTC
[reply]
Re: What's the answer to this puzzle? Most unique/golfed solution? (fun)
by Anonymous Monk on Sep 24, 2011 at 04:06 UTC

    55 characters:

    perl -E'$_=1;say,s/(.)\1*/$&=~y...c.$1/ge while$i++<19'

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