You should be able to solve this

A common algorithm for generating pseudorandom numbers is a "linear congruential generator" which uses the following procedure:

1) A positive integer m and two integers a and b between 0 and m−1 are fixed.

2) A seed r(0) between 0 and m−1 is input.

3) After that, numbers are generated by the recurrence r(n+1) = ar(n)+b (mod m).  (So that 0 <= r(n+1) <= m−1).


The following sequence of numbers was generated in this way.

6543
6331
9584
9025
3911

Find a,b, and m.

(crossposted from /sci/, cuz i herd u liek math).

>>32
will take forever to give an answer
Did you miss the part where the answer was given less than an hour after you posted your problem? And it was most likely not seen immediately.

>>27
Here's one equivalent to my original solution, only much cleaner:

getb a m n nn = mod (nn - n * a) m

solve = [ (a,b,m) | m <- [9585 ..  ],
                    a <- [   1 .. m],
                    b <- [getb a m 6543 6331],
                    b == getb a m 6331 9584,
                    b == getb a m 9584 9025,
                    b == getb a m 9025 3911]

It runs in ten seconds.

>>40
That's not a for loop.  He used HASKELL NOMADS.

The code but he   never died in   the first place   elegant expression of   a fundamental type   of logic The.

lol @ 'You should be able to solve this'

>>43
FrozenVoid is getting better at _English!

>>45
Please never mention _{THE FROZEN NAME} again!