import List (sort)

solveCoin :: Integer -> [Integer] -> [[Integer]]
solveCoin total coins = 
  let coins' = reverse $ sort coins
  in takeCoins coins' [] total

takeCoins :: [Integer] -> [Integer] -> Integer -> [[Integer]]
takeCoins [] _ _ = []
takeCoins cs xs rest = 
  let c = head cs
      cs' = tail cs
      possibleCombinations = case signum (rest - c) of
        -1 -> []
        0 -> [c:xs]
        1 -> takeCoins cs (c:xs) (rest - c)
  in possibleCombinations ++ (takeCoins cs' xs rest)

main = print $ solveCoin 10 [1, 5, 10, 50, 100, 500]

[[10],[5,5],[1,1,1,1,1,5],[1,1,1,1,1,1,1,1,1,1]]