46RRECTP6... solution

The original challenge: https://www.reddit.com/r/ChallengeAccepted/comments/2ifbnp/i_challenge_you_to_decode_this_string/

Answer: It's base32. 0-9A-V

    32  10
    ------
    0   0
    1   1
    2   2
    3   3
    4   4
    5   5
    6   6
    7   7
    8   8
    9   9
    A   10
    B   11
    C   12
    D   13
    E   14
    F   15
    G   16
    H   17
    I   18
    J   19
    K   20
    L   21
    M   22
    N   23
    O   24
    P   25
    Q   26
    R   27
    S   28
    T   29
    U   30
    V   31

Because 2^5 = 32, one character encodes 5 bits. And because ASCII characters are 8 bits, that means it gets pretty
complicated.

    H           e           l           l           o
    4    8      6    5      6    c      6    c      6    f
    0100-1000   0110-0101   0110-1100   0110-1100   0110-1111
    0100100001100101011011000110110001101111
    01001 00001 10010 10110 11000 11011 00011 01111
    9     1     18    22    24    27    3     15
    91IMOR3F

I don't remember how I dealt with trailing bits. I probably just padded it to the right with 0's (edit: padded to the left, actually), or maybe python has a built-in way to convert to base32 (edit: *from* base32, but not *to*), and python's base32 happens to be the same base32 as described here (edit: it is).

I still have said (very old and poorly written to such a degree that I can't even understand what it's trying to do) python program, which I wrote for doing this conversion

    $ b32c.py b 46RRECTP62T3LDHGN8QBFDPPI282KD1II0SR5CDP6AT10ETNN4P10D5PI0OJ1DPGMSO9E
    Congratulations! The secret word is banana.

So there you go.

Source code: https://pastebin.com/tAerN5tF
Improved source code (2018-07-29): https://pastebin.com/pH4fxCLM
Old explanation: https://pastebin.com/epDEqVKV