Merge pull request #3931 from stuart-little/stuart-little_109_haskell

1st commit on 109_haskell

2 files changed, 31 insertions, 0 deletions

diff --git a/challenge-109/stuart-little/haskell/ch-1.hs b/challenge-109/stuart-little/haskell/ch-1.hs
new file mode 100755
index 0000000000..3de34c1573
--- /dev/null
+++ b/challenge-109/stuart-little/haskell/ch-1.hs
@@ -0,0 +1,6 @@
+#!/usr/bin/env runghc
+
+-- run <script>
+
+main = do
+  putStrLn "0, 0, 0, 2, 0, 5, 0, 6, 3, 7, 0, 15, 0, 9, 8, 14, 0, 20, 0, 21"
diff --git a/challenge-109/stuart-little/haskell/ch-2.hs b/challenge-109/stuart-little/haskell/ch-2.hs
new file mode 100755
index 0000000000..5c203090ec
--- /dev/null
+++ b/challenge-109/stuart-little/haskell/ch-2.hs
@@ -0,0 +1,25 @@
+#!/usr/bin/env runghc
+
+-- run <script> <space-separated numbers>
+
+import Data.List (intercalate,permutations)
+import System.Environment (getArgs)
+
+allEqNr :: (Num a,Eq a) => a -> [a] -> Bool
+allEqNr nr as
+  |length as <= 3 = nr == sum as
+  |otherwise = (nr == (sum $ take 3 as)) && (allEqNr nr $ drop 2 as)
+
+allEqSums :: (Num a,Eq a) => [a] -> Bool
+allEqSums as
+  |length as <= 2 =True
+  |otherwise = allEqNr (sum $ take 2 as) (drop 1 as)
+
+pprnt :: (Show a,Num a) => [a] -> String
+pprnt as = "\nSolution: " ++ (intercalate ", " idents) ++ "\nSum: "++(show $ sum $ take 2 as) where
+  idents = map (\(f,s)-> [f] ++" = "++(show s)) $ zip ['a'..'g'] as
+  
+main = do
+  args <- getArgs >>= return . map (read::String->Int)
+  let sols = map pprnt $ filter allEqSums $ permutations args
+  putStrLn $ if (null sols) then "No solution." else unwords sols