Mark, I think your approach is clean and simple, but loses the advantage of decomposing the problem into useful constituent parts. I have written this up in more detail at http://blog.runcoderun.com/post/145675117/tdd-in-a-functional-language-uncle-bobs-bowling .
Stu > I think you guys are really overthinking this problem. Because > Clojure inherits Java's stack limitations, we tend to get hung up on > converting elegant recursive code into loop/recur/accumulator > structures. But here, we have a problem that we know isn't going to > blow the stack, so just think recursively and you end up with a > solution that is short and easy to understand: > > (use 'clojure.contrib.test-is) > > ; A game is a sequence of numbers, representing how many pins were > knocked down for that roll > > (defn sum [s] (reduce + s)) > (defn score [game] > (cond > (< (count game) 3) (sum game), > > (= (first game) 10) (+ (sum (take 3 game)) > (score (drop 1 game))), > > (= (sum (take 2 game)) 10) > (+ (sum (take 3 game)) (score (drop 2 game))), > > :else (+ (sum (take 2 game)) (score (drop 2 game))))) > > (deftest sample-games > (is (score [1 0 1 10 2 2 10 3 3 10 1 10 3 10 10 1 2]) 108) > (is (score [1 0 1 10 2 2 10 3 3 10 1 10 3 10 1 10 10 8 0]) 121) > (is (score [1 0 1 10 2 2 10 3 3 10 1 10 3 10 1 10 8 10 9]) 120)) > > > ;;;;;;;;;;;; > You can improve efficiency by enforcing an input of vectors and using > subvec, or you can keep the generality of sequences but change the > first test to something like (= (count (take game 3)) 3), but really, > why bother doing *anything* at the expense of clarity for a problem > where the inputs are so small that efficiency is a non-issue. > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
