Jeff
Actually, the upper limit would be based on the alpha key. I don't remember, so I looked on Wikipedia. If I understand correctly, 27 different possible characters in 40 places would be
P(n,r) = n! / (n - r)!
= 40! / 13!
I'm not even going to try simplify, but I think it's even...
Thanks for all the suggestions.
While non-perfect hashes are a good way to reduce the required number of probes, in my case I don't believe it's worth the effort. The table isn't big enough to justify the added complexity. I just thought it would be cool to reduce the look-up to O(1).
Ross
Thanks for the fast responses, guys.
I was afraid that the index size was too small, but I wanted someone to confirm my suspicions. O(n) it is, then - brute force search to the rescue!
Thanks again for your help.
Hi all
Basically, I'm looking for a fingerprinting or perfect hash function.
The key is 40 alpha characters, specifically \b[A-Z_]{40}\b.
The index is a 12-digit integer.
The function must be deterministic, i.e. if a key maps to an index, it must always map to the same index.
The...