Just goes to show that Knuth was right

One other thing occurred to me as a possible optimization: I'm raising 10 to some integer power a lot. Why not try

powersOfTen = [10 ^ i | i <- [0..]]

tenToThe :: Int -> Integer

tenToThe n = powersOfTen !! n

which would memoize those pesky exponentiations? (!! lets you retrieve elements from lists sort of as if they were arrays, with "subscripts" starting at zero.)

It was easy enough to try out, but the results were disappointing. Even on my Eee 900A, with a 32-bit processor that you'd think would get the most benefit, the variations in time output from one run to the next were large enough that I can't say with certainty that it made any difference at all. Time output for the first large data set:

real    0m1.093s
user    0m1.068s
sys     0m0.016s

For the second large data set:

real    0m5.531s
user    0m5.472s
sys     0m0.044s

These are with the program compiled--I still haven't done the file opening code.