Data commit

Task/Dice-game-probabilities/Haskell/dice-game-probabilities.hs

@@ -0,0 +1,22 @@
+import Control.Monad (replicateM)
+import Data.List (group, sort)
+
+succeeds :: (Int, Int) -> (Int, Int) -> Double
+succeeds p1 p2 =
+  sum
+    [ realToFrac (c1 * c2) / totalOutcomes
+    | (s1, c1) <- countSums p1
+    , (s2, c2) <- countSums p2
+    , s1 > s2 ]
+  where
+    totalOutcomes = realToFrac $ uncurry (^) p1 * uncurry (^) p2
+    countSums (nFaces, nDice) = f [1 .. nFaces]
+      where
+        f =
+          fmap (((,) . head) <*> (pred . length)) .
+          group . sort . fmap sum . replicateM nDice
+
+main :: IO ()
+main = do
+  print $ (4, 9) `succeeds` (6, 6)
+  print $ (10, 5) `succeeds` (7, 6)