gmane.comp.lang.perl.qotw.discuss

Perl QOTW #2010-02-22 - Freecell Scans with Short Solutions

Shlomi Fish — 2010-02-22T15:31:32

IMPORTANT: Please do not post solutions, hints, or other spoilers
until at least 60 hours after the date of this message.  Thanks.

Requests for clarifications and other discussion would be OK.

---------------

Today I'm borrowing the collective wisdom of the Perl Quiz-of-the-Whatever
forum for an algorithmic task I need to accomplish for my own project.
The project in question is Freecell Solver ( http://fc-solve.berlios.de/ ),
which is an automated solver for http://en.wikipedia.org/wiki/FreeCell and 
several other types of card solitaire. 

fc-solve starts from the initial layout of the solitaire game and recurses
into more and more positions, which are counted by the solver's iterations,
until it reaches the final, solved state where all cards were moved to the
foundations.

After a certain number of iterations (which are roughly indicative of 
how long it took it to run), it yields a solution of a certain length ,which 
is desired to be as short as possible. Note that it may also report that it
is unab

Perl 'Medium' Quiz-of-the-Whatever for 2009-08-11 : Plusified Equations

Shlomi Fish — 2009-08-11T14:55:06

IMPORTANT: Please do not post solutions, hints, or other spoilers
until at least 60 hours after the date of this message.  Thanks.

---------------

We are given two positive integers $L and $R we need to find Plusified 
expressions of both for which Eval($E_L) == Eval($E_R). So what is a plusified 
expression? It is an expression where we can choose whether to add a single 
"+" between any consecutive digit. So for example the number 123 has the 
following plusified expression:

* 123
* 12+3
* 1+23
* 1+2+3


So if we are given 123 and 96 we can form the following plusified equation:

* 12+3 == 9+6

Your mission is to write a Perl program (or an equivalent program in any 
programming language) that will find all solutions to the plusified equation 
of two numbers given as input. To normalise the output we'll rule that:

1. The equations should be given one at each line.

2. They will be sorted so consecutive digits will take precedence over "+"'s.

3. A "+" has no surrounding spaces.

4. The = sign does have