algorithm

[chrisyt]

anybody have a good algorithm for seeing if say 6 or 7 cards contain a gut shot draw? thats an example.
currently i'm going the long way if X=2 and X2=3 andX3=4 and X4=5 then its a gut shot (thats an example) programming in Java. was wondering if anybody knew of a more succint method, maybe this is the wrong forum altogether but thougth i'd give it a try.
thanks for any ideas
chris

[fiskebent]

Here's how I'd do it (in pseudo-code):
<font class="small">Code:</font><hr /><pre>
int CardPresent[13] = (0, 0, 0, 0, 0... );
for (i=0; i&lt;NoOfCardsInHand; i++) {
CardPresent[ValueOfCard(CardInHand[i])] = 1;
}
for (i=0; i&lt;(13-5); i++) {
int NumberOfCardsInRange = 0;
for (j=i; j&lt;(i+5); j++) {
NumberOfCardsInRange += CardPresent[j];
}
if (NumberOfCardsInRange == 4) {
if ((CardPresent[j] == 1) &amp;&amp; (CardPresent[j+4] == 1))
print "Gutshot draw present";
else
print "Open-ended straight draw present";
}
}
</pre><hr />
First I mark what cards are present in an array.

Then I loop over the possible 5-card ranges, counting how many cards are present in those ranges. If 4 cards are present and both the top and the bottom card in the range is present, then you have a gutshot draw.

Edit: It'll falsely mark A, 2, 3, 4 as an open-ended straight draw. And you need to add some code to handle that aces count as high and low cards. Gotta leave some work for you [img]/images/graemlins/smile.gif[/img]