haskell pinball

gistfile1.hs

{-# OPTIONS_GHC -Wall -O2 #-}

module Main where

main :: IO()
main = interact (solve . readTestCases)

-- This builds a list of lists representing the problem
readTestCases :: String -> [[Int]]
readTestCases = parse 1 . map read . words
-- Input:  Row#, list of ints from input
-- Output: returns a list of lists
parse :: Int->[Int]->[[Int]]
parse _ [] = []
parse 1 (_:x:xs)   = [x]:parse 2 xs
parse i xs = (take i xs):parse (i+1) (drop i xs)

-- Solve the problem for one test case
solve :: [[Int]] -> String
solve xs = show (getScore 0 0 xs)

getScore :: Int->Int->[[Int]]->Int
getScore r c xs
    | r >= (length xs) = 0
    | c >= length (xs!!r) || c<0 = 0
    | otherwise = ((xs!!r)!!c) + max left right
      where
        left = getScore (r+1) c xs
        right = getScore (r+1) (c+1) xs