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@M4GNV5
Last active November 7, 2018 21:31
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import Data.Ord
import Data.List
import Data.Function
dice n = [1..n]
combinations xs ys = concat $ map (\y -> map (\x -> x : y) xs) ys
diceCombinations n k = foldr (combinations) (map return diceN) (replicate (k - 1) diceN)
where
diceN = dice n
mapFst f xs = map (\(x, y) -> (f x, y)) xs
isEq :: Ordering -> Bool
isEq EQ = True
isEq _ = False
elementCounts :: (a -> a -> Ordering) -> [a] -> [(a, Int)]
elementCounts f xs = map (\ys -> (head ys, length ys)) $ groupBy (\x y -> isEq $ f x y) $ sortBy f xs
diceModuloCounts k = groupModCounts
where
diceCounts = elementCounts compare $ map sum $ diceCombinations 6 k
modCounts = mapFst (`rem`k) diceCounts
groupedMods = groupBy ((==) `on` fst) $ sortBy (compare `on` fst) modCounts
groupModCounts = map (\l -> (fst $ head l, sum $ map snd l)) groupedMods
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