[thechat] Programming Problem

[Joe Crawford]

Beau Hartshorne wrote:
> My girlfriend introduced me to a card game called "24". In the game,
> aces are valued at 1 and royalty is valued at 10. Four cards are laid
> out on the table, and the first person to figure out a way to somehow
> get the cards to add/multiply/subtract/divide evenly to 24 wins the
> round. Each card can be used in the calculation only once.
> 
> So if these four cards were laid out: 7 3 1 3
> One possible solution is: 7*3+3*1
> 
> For these cards: 2 10 1 2
> One possible solution is: (1+2)*(10-2)
> 
> My question is how would you go about writing a computer program to find
> every possible solution for every possible combination of cards?
> 
> Ideas?

In php - something like --- (don't laugh, ( can tell you that this is
absolutely the least efficient way to code this. And more, I can't get
it to do the math! But the concept is arrays of the possible, and
iterate through them all.

This gets to:
3*3*Jack-10 = 3*3*10-10 = 
3*3*Jack-Jack = 3*3*10-10 = 
3*3*Jack-Queen = 3*3*10-10 = 
3*3*Jack-King = 3*3*10-10 = 

Fatal error:  Maximum execution time of 60 seconds exceeded in
/<deleted>p on line 28

Somebody should tell rudy about this thread - this seems up his alley. I
bet he could do it in SQL! I'll cc him. :-)

	- Joe <http://artlung.com/>

<pre><?
$card_values  = array(  1, 2,   3,  4,  5,  6,  7,  8,  9,  10,  10, 10,
10);
$card_names   =
array("Ace","2","3","4","5","6","7","8","9","10","Jack","Queen","King");
$operators    = array("+","-","/","*");

for($card1=0;$card1<sizeof($card_names);$card1++)
 {
 for($op1=0;$op1<sizeof($operators);$op1++)
  {
   for($card2=0;$card2<sizeof($card_names);$card2++)
    {
     for($op2=0;$op2<sizeof($operators);$op2++)
      {
       for($card3=0;$card3<sizeof($card_names);$card3++)
	    {
         for($op3=0;$op3<sizeof($operators);$op3++)
          {
           for($card4=0;$card4<sizeof($card_names);$card4++)
            {
     echo $card_names[$card1];
     echo $operators[$op1];	
     echo $card_names[$card2];
     echo $operators[$op2];	
     echo $card_names[$card3];
     echo $operators[$op3];	
     echo $card_names[$card4];

      $card_operation =
      $card_values[$card1]
      .$operators[$op1]	
      .$card_values[$card2]
      .$operators[$op2]	
      .$card_values[$card3]
      .$operators[$op3]	
      .$card_values[$card4];

       echo " = $card_operation = ";
       echo "\n";
          }
         }	
       }
     }	
   }
  }	
}
?></pre>



-- 
...................  Joe Crawford \\ Web Design & Development
.....  mailto:jcrawford at avencom.com \\ http://www.avencom.com
.... San Diego \\ CA \\ USA \\ AVENCOM: Set Your Sites Higher