From 5a1bfa3b3192df57cc06a8e7312454c4f0ffafc5 Mon Sep 17 00:00:00 2001
From: Wesley Kerfoot <378351+weskerfoot@users.noreply.github.com>
Date: Mon, 27 Jan 2020 14:18:50 -0500
Subject: [PATCH] Create sorted_digits.hs

---
 sorted_digits.hs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 sorted_digits.hs

diff --git a/sorted_digits.hs b/sorted_digits.hs
new file mode 100644
index 0000000..7b6b3df
--- /dev/null
+++ b/sorted_digits.hs
@@ -0,0 +1,18 @@
+import Data.List
+
+digits :: Int -> [Int]
+digits n = unfoldr nextDigit n where
+  nextDigit 0 = Nothing
+  nextDigit c = Just $ (c `mod` 10, c `div` 10)
+
+isSorted :: Int -> Bool
+isSorted n = (all (uncurry (<=)) ds') || (all (uncurry (>=)) ds'') 
+  where ds = digits n
+        ds' = zip ds (maxBound : ds)
+        ds'' = zip ds (minBound : ds)
+
+main = do
+  print $ isSorted 123456
+  print $ isSorted 1234561
+  print $ isSorted 97541
+  print $ isSorted 99431