0 = A
1 = B
...
25 = Z
26 = AA
27 = AB
...
701 = ZZ
702 = AAA
I cannot think of any solution that does not involve loop-bruteforce :-(
I expect a function/program, that accepts a decimal number and returns a string as a result.
o=map(['A'..'Z']:)$[]:o
e=(!!)$o>>=sequence
Other entries aren't counting the driver, which adds another 40 chars:
main=interact$unlines.map(e.read).lines
A new approach, using a lazy, infinite list, and the power of Monads! And besides, using sequence makes me :), using infinite lists makes me :o