Add Haskell solution for Problem 36

Haskell/p036.hs

@@ -0,0 +1,18 @@
+-- The decimal number, 585 = 1001001001_2 (binary), is palindromic in both bases.
+--
+-- Find the sum of all numbers, less than one million, which are palindromic in base 10 and base 2.
+--
+-- (Please note that the palindromic number, in either base, may not include leading zeros.)
+
+toBinary :: Int -> [Int]
+toBinary 0 = []
+toBinary 1 = [1]
+toBinary n = toBinary (n `div` 2) ++ [n `mod` 2]
+
+doublePalindrome :: Int -> Bool
+doublePalindrome n = show n == reverse (show n) && toBinary n == reverse (toBinary n)
+
+main = do
+    let result = sum $ filter doublePalindrome [1..999999]
+    putStrLn $ "Project Euler, Problem 36\n"
+        ++ "Answer: " ++ show result