Subj : Re: combo numbering
To   : comp.programming
From : Ed Prochak
Date : Thu Oct 06 2005 03:12 pm


bob@coolgroups.com wrote:
> If you have 52 cards and you choose 7, there are 133,784,560
> possibilities.
>
> So, let's say you have 7 playing cards. Is there an easy way to convert
> these cards into a number between 0 and 133,784,559?

consider a 52bit number.
bit position 0 is ace of spades
bit position 1 is duece of spades
bit position 2 is 3 of spades ... etc.

the 7card hand is a 52bit number with seven 1 bits.

You could also use four 13bit numbers , one per suit.
that's easily just 4 ints.

HTH,
  ed

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