haskell problem 30

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+-- Digit fifth powers
+--
+-- Problem 30
+-- Surprisingly there are only three numbers that can be written as the sum of fourth
+-- powers of their digits:
+--
+-- 1634 = 14 + 64 + 34 + 44
+-- 8208 = 84 + 24 + 04 + 84
+-- 9474 = 94 + 44 + 74 + 44
+-- As 1 = 14 is not a sum it is not included.
+--
+-- The sum of these numbers is 1634 + 8208 + 9474 = 19316.
+--
+-- Find the sum of all the numbers that can be written as the sum of fifth powers of
+-- their digits.
+
+
+-- there is a limit but who cares (me but im lazy)
+main = do
+    let pow5 = [x | x <- [2..300000], digitsSumPow 5 x == x]
+    -- print (pow5)
+    print (sum pow5)
+
+digitsSumPow :: Int -> Int -> Int
+digitsSumPow power nb = sum $ map (^power) (digits nb)
+
+digits x = reverse $ revDigits x
+
+revDigits :: Int -> [Int]
+revDigits 0 = []
+revDigits x = x `mod` 10 : revDigits (x `div` 10)
+