Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Out of extreme boredom, I wrote the following code to solve 24 puzzles. For those of you that have never played the game 24, you must make the number 24 out of 4 other non-zero numbers using the basic 4 arithmetic operations. For example, the numbers 5, 5, 8, 8 can be made to equal 24 bacause 5*5-8/8=24. With that in mind, the following code solves 24 puzzles by basically trying every possible combination of operations on the four numbers (I think), and then displaying the unique solutions or an error message if no solutions are found. I use a regular expression to introduce parentheses into the expressions to be evaluated to account for solutions that should be evaluated against the order of operations. My two questions are:

1. As you can see in the beginning of my program, I use an array called @optimize_me to store the different orders that numbers will be evaluated. I want to be able to easily convert this program to solve 5, 6, or more numbers. Is there an easier way to to go about this besides the array method I used? Maybe a way to dynamically create such an array?

2. The other problem with solving with more than 4 numbers is that the regular expression that inserts parantheses quickly gets unwieldly. Is the a better way to go about this step or a way to create a regular esxpression that will work for all cases? Here is my code:

#!/usr/bin/perl while (<>) { undef %results; chop; s/ //g; (/^quit$/i) && exit(0); ((/^(?:\d+:){3}\d+$/) && (@given1=split(/:/,$_))) || ((/^\d{4}$/) && ( +@given1=split('',$_))) || (print ("format error: $_\n"),next); @func=('+','*','-','/'); @optimize_me=('0123','0132','0213','0231','0312','0321','1023','1032', +'1203','1230','1302','1320','2013','2031','2103','2130','2301','2310' +,'3012','3021','3102','3120','3201','3210'); while (@optimize_me) { $must=shift(@optimize_me); @select=split('',$must); @given=($given1[$select[0]],$given1[$select[1]],$given1[$select[2]],$g +iven1[$select[3]]); for ($var1=0;$var1<4;$var1++) { for ($var2=0;$var2<4;$var2++) { for ($var3=0;$var3<4;$var3++) { $expression=$given[0].$func[$var1].$given[1].$func[$var2]. +$given[2].$func[$var3].$given[3]; $trans1=$trans2=$trans3=$expression; $trans1=~s/(\d+[\+-]\d+)/\($1\)/; $trans3=~s/(\d+[\+\-\*\/])(\d+[\+-]\d+)/$1\($2\)/; $trans2=~s/((\d+[\+-])+\d+)/\($1\)/g; $tempt=eval($expression); $tempt1=eval($trans1); $tempt2=eval($trans2); $tempt3=eval($trans3); ($tempt==24 && print("$expression\n") && ($results{$expres +sion}=1)) unless $results{$expression}; ($tempt1==24 && print("$trans1\n") && ($results{$trans1}=1 +)) unless $results{$trans1}; ($tempt2==24 && print("$trans2\n") && ($results{$trans2}=1 +)) unless $results{$trans2}; ($tempt3==24 && print("$trans3\n") && ($results{$trans3}=1 +)) unless $results{$trans3}; } } } } (%results) ? print "Found ",$dumb1=keys(%results)," different ways to +form 24 from @given\n" : print "Could not find any ways to make 24 fr +om @given1\n"; }

Any help or comments of any kind are greatly appreciated.

Thanks for your time,

tigervamp


In reply to Solving 24 puzzles by tigervamp

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others about the Monastery: (5)
    As of 2014-09-20 05:27 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      How do you remember the number of days in each month?











      Results (153 votes), past polls