Quote from: CaeZaR on May 20, 2014, 04:22:41 PM

I realize I botched this when I caught that after z should come 21 not 11 (all the leading unprinted digits are 1s), so here is the fixed version:

Code:

Options[Base58Encode] = {n -> None};
Base58Encode[x_Integer, OptionsPattern[]] :=
StringJoin[
StringTake[
"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz",
Partition[
1 + If[OptionValue[n] === None, IntegerDigits[x, 58],
IntegerDigits[x, 58, OptionValue[n]]], 1]]]

You can call it with a single parameter and get the shortest version of the number, or specify the number of digits (n) as an option.

Code:

i = RandomInteger[2^256]
Base58Encode[i]
Base58Encode[i, n -> 50]

I'll fix the decode in the next post, as it is wrong too. Sorry about that.

Hello CaeZar. I like the way you tested the encode/decode functions using the random list. That's what I do too.

Your encode function is not quite correct, however. It is still not dealing with the leading "1"s properly. I think the option value "n" needs to be the amount of bytes to assume the number being encoded is composed of. And then add a "1" for every byte that is zero. The encoding for bitcoin is strange. It is documented here and we were discussing it here.

Like I said in the OP, you can fix this and resubmit to claim the bounty.