PartialPermutations.hs

permutationWithMod :: Integer -> Integer -> Integer -> Integer
permutationWithMod numTake setSize modValue =
  let nums = [(setSize - numTake + 1)..setSize]
  in foldl (\acc n -> (acc * n) `mod` modValue) 1 nums

main :: IO()
main = do
  setSize <- getLine
  numTake <- getLine
  modValue <- getLine
  print $ permutationWithMod (read numTake) (read setSize) (read modValue)