Haskell Quiz/Maximum Sub-Array/Solution Ninju: Difference between revisions
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[[Category:Haskell Quiz solutions|Maximum Sub-Array]] | |||
No clever stuff here unfortunately. | No clever stuff here unfortunately. | ||
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let maxSubArray = maximumSubArray array | let maxSubArray = maximumSubArray array | ||
putStrLn $ "The maximum sub array in " ++ show array ++ " is " ++ show maxSubArray | putStrLn $ "The maximum sub array in " ++ show array ++ " is " ++ show maxSubArray | ||
maximumSubArray :: [Integer] -> [Integer] | maximumSubArray :: [Integer] -> [Integer] | ||
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-- e.g. slices [1,2,3] = [[1], [1,2], [1,2,3], [2], [2,3], [3]] | -- e.g. slices [1,2,3] = [[1], [1,2], [1,2,3], [2], [2,3], [3]] | ||
slices :: Eq a => [a] -> [[a]] | slices :: Eq a => [a] -> [[a]] | ||
slices [] = | slices [] = [] | ||
slices xs = | slices xs = tail $ inits xs ++ slices (tail xs) | ||
</haskell> | </haskell> | ||
Latest revision as of 02:28, 22 August 2008
No clever stuff here unfortunately.
module Main where
import System.Environment
import Data.List
import Data.Ord
main :: IO ()
main = do args <- getArgs
let array = map read args
let maxSubArray = maximumSubArray array
putStrLn $ "The maximum sub array in " ++ show array ++ " is " ++ show maxSubArray
maximumSubArray :: [Integer] -> [Integer]
maximumSubArray = last . sortBy (comparing sum) . slices
-- returns all sub lists of a given list not including the empty list
-- e.g. slices [1,2,3] = [[1], [1,2], [1,2,3], [2], [2,3], [3]]
slices :: Eq a => [a] -> [[a]]
slices [] = []
slices xs = tail $ inits xs ++ slices (tail xs)