[Haskell-cafe] Analyzing slow performance of a Haskell program

[Chris Yuen]

Hello Cafe,

I was trying to solve ITA Software's "Word Nubmers" puzzle (
http://www.itasoftware.com/careers/puzzle_archive.html) using a brute force
approach.

Here's a my version of a quick recap of the problem:

> A wordNumber is defined as
>
> wordNumber 1 = "one"
> wordNumber 2 = "onetwo"
> wordNumber 3 = "onethree"
> wordNumber 15 =
"onetwothreefourfivesixseveneightnineteneleventwelvethirteenfourteenfifteen"
> ...
>
> Problem: Find the 51-billion-th letter of (wordNumber Infinity); assume
that letter is found at 'wordNumber x', also find 'sum [1..x]'