cards - comp.programming

bob@coolgroups.com wrote: ) Let's say you want to iterate through all of the possible combinations ) that occur when you choose 7 cards from a fifty two card deck. Anyone ) know the best way to do this? What the best way is depends on why you would want to iterate through all possible combinations, how you want to represent those combinations, and probably a lot of other factors as well. I can probably come up with some code for this, but I doubt it will be the 'best way' in every way. SaSW, Willem -- Disclaimer: I am in no way responsible for any of the statements made in the above text. For all I know I might be drugged or something.. No I'm not paranoid. You all think I'm paranoid, don't you ! #EOT

<bob@coolgroups.com> wrote in message news:1128448274.935279.78050@g47g2000cwa.googlegroups.com... > Let's say you want to iterate through all of the possible combinations > that occur when you choose 7 cards from a fifty two card deck. Anyone > know the best way to do this? Are the same cards, but in a different order, a different combination? -- Roger

I'm trying to analyze the Texas Holdem probabilities. Roger Willcocks wrote: > <bob@coolgroups.com> wrote in message > news:1128448274.935279.78050@g47g2000cwa.googlegroups.com... > > Let's say you want to iterate through all of the possible combinations > > that occur when you choose 7 cards from a fifty two card deck. Anyone > > know the best way to do this? > > Are the same cards, but in a different order, a different combination? > > -- > Roger

bob@coolgroups.com wrote: ) Roger Willcocks wrote: )> <bob@coolgroups.com> wrote in message )> news:1128448274.935279.78050@g47g2000cwa.googlegroups.com... )> > Let's say you want to iterate through all of the possible combinations )> > that occur when you choose 7 cards from a fifty two card deck. Anyone )> > know the best way to do this? )> )> Are the same cards, but in a different order, a different combination? ) ) I'm trying to analyze the Texas Holdem probabilities. So order doesn't matter, I guess ? Well then it's real easy: for (c1 = 0; c1 < 52-6; c1++) for (c2 = c1+1; c2 < 52-5; c2++) for (c3 = c2+1; c3 < 52-4; c3++) for (c4 = c3+1; c4 < 52-3; c4++) for (c5 = c4+1; c5 < 52-2; c5++) for (c6 = c5+1; c6 < 52-1; c6++) for (c7 = c6+1; c7 < 52-0; c7++) do_something(c1,c2,c3,c4,c5,c6,c7); If you want a more general routine that can handle different numbers of cards, that's not much more complex, but quite a bit harder to think of. SaSW, Willem -- Disclaimer: I am in no way responsible for any of the statements made in the above text. For all I know I might be drugged or something.. No I'm not paranoid. You all think I'm paranoid, don't you ! #EOT

"Willem" <willem@stack.nl> wrote in message news:slrndk5tt2.rmp.willem@toad.stack.nl... > bob@coolgroups.com wrote: > ) Roger Willcocks wrote: > )> <bob@coolgroups.com> wrote in message > )> news:1128448274.935279.78050@g47g2000cwa.googlegroups.com... > )> > Let's say you want to iterate through all of the possible > combinations > )> > that occur when you choose 7 cards from a fifty two card deck. > Anyone > )> > know the best way to do this? > )> > )> Are the same cards, but in a different order, a different combination? > ) > ) I'm trying to analyze the Texas Holdem probabilities. > > So order doesn't matter, I guess ? According to http://www.learn-texas-holdem.com/how-texas-holdem-is-played.htm (now there's an apposite url, even if I say so myself), each player is dealt two cards and has to select a poker hand from those two cards and five separately dealt pool cards usable by all players. Betting occurs after the player receives two cards, and after the pool gets three, four then five cards. So it looks like order does matter. -- Roger

bob@coolgroups.com wrote: > why does it look to you like order matters? > In the loops solution (seven nested loops), the last variable never takes the first value. Translating to cards, it means that you're assuming that the last card on the table can never be the ace of spades. This assumption would change the probabilities considerably (and is definitely wrong for a game of poker). So if you want a call/fold/raise winning probabilities after each card, you can't just go through all possible 7-card sets, you have to look at the order of the cards in each set as well.

In article <di0eaa$pf$1@reader-00.news.insnet.cw.net>, Omri Barel <spammer@b2z.com> wrote: ... >In the loops solution (seven nested loops), the last variable never >takes the first value. Translating to cards, it means that you're >assuming that the last card on the table can never be the ace of spades. > >This assumption would change the probabilities considerably (and is >definitely wrong for a game of poker). > >So if you want a call/fold/raise winning probabilities after each card, >you can't just go through all possible 7-card sets, you have to look at >the order of the cards in each set as well. I'm not sure it's quite that bad. Each player starts out with 2 private cards, and then five public cards are made available in three groups: the flop (the first 3 cards), the turn (the fourth card), and the river (the last card). So, the set of 7 cards is made of 4 subsets: Size Name ===== ===== 2 Private (This is unique to each player) 3 Flop 1 Turn 1 River Within the Private and Flop sets, ordering doesn't matter. This reduces the search space by a factor of 12. One complication in all this is that the value of a given set of 7 cards is strongly influenced by the potential value of the public cards by themselves. That is, if I'm holding a pair of 2's, they aren't worth as much if the public cards look like 4,4,3,3,3 or 4,5,6,7,10. I would expect considerations like those to have a big role in deciding the overall worth of a hand. -Mike -- http://www.mschaef.com

Roger Willcocks said: > <bob@coolgroups.com> wrote in message > news:1128448274.935279.78050@g47g2000cwa.googlegroups.com... >> Let's say you want to iterate through all of the possible combinations >> that occur when you choose 7 cards from a fifty two card deck. Anyone >> know the best way to do this? > > Are the same cards, but in a different order, a different combination? No. They are a different permutation, but he specifically asked for combinations, not permutations. -- Richard Heathfield "Usenet is a strange place" - dmr 29/7/2005 http://www.cpax.org.uk email: rjh at above domain (but drop the www, obviously)