I coded this from a puzzle a friend showed to me. 
#!/usr/bin/perl -w
use strict;undef $/;$_=<>;while(m+^(\d)(\1*)+)
{print length($1.$2),$1;s;$1$2;;;}
########################################################
#
#  This works best with the numbers 1, 2, and 3.
#
########################################################

[download]

Replies are listed 'Best First'.
Re: 123 Digit Counter
by Juerd (Abbot) on Mar 13, 2002 at 20:56 UTC

    What exactly does/should it do? Could you give an example please? (I put in some numbers, and got output, but have no idea what it means) 

    U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

[reply]
      It's an encoding of a puzzle, of which one partial series is: 
      121
111211
311221
13212211

      [download]
      The trick is to find out what the rule is.
      Rob
      --
      Nar! Pushdug ghashnurbhar! ($#@! Stinking pile of code!)
[reply]
[d/l]
        Each new number is composed of digit pairs which count the consecutive occurences of digits in the last number:

        1 2 1 -> 11 12 11 (one '1', one '2', one '1')
        111 2 11 -> 31 12 21 (three '1's, one '2', two '1's)
        3 11 22 1 -> 13 21 22 11 (one '3', two '1's, two '2's, one '1')

        so the next number should be:

        1 3 2 1 22 11 -> 11 13 12 11 22 21 = 111312112221

        I first encountered this sequence as a method of compressing long strings of repeated numbers:

        888888884444444999222222211111116644444 ->
        88743972712654

        Though obviously it's not a good choice for compressing something like:

        123456789123456789 ->
        111213141516171819111213141516171819

        chr0
        ----
        perl -le'$$=substr(%{*::}->{_},2,1);print+(map{$$++for(1..$_);$$}(2,5,10)),$|'
[reply]

        The trick is to find out what the rule is.

        And what would the "rule" in your example be? And why?

        I really haven't the slightest idea what this is, and what it is supposed to do, but it looks interesting 

        U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

[reply]

Back to Obfuscated Code