> Just replicating the original module, including a fairly straight port to C

This doesn't mean you have to ignore a fast algorithm for the proper task.

Mapping B => b0=11 is most likely producing the same effect like mapping B to two digits b1,b2 < 10 with b1 for odd and b2 for even positions.

From there on you can still use the fast algorithm.

Otherwise I don't understand the point of the whole thread and am quizte happy I didn't try to waste time on coding an even faster solution.

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

In reply to Re^12: Faster Luhn Check Digit Calculation? by LanX
in thread Faster Luhn Check Digit Calculation? by kschwab

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