Add the AZ entry

Author: mnvr

05.eli5.hs

@@ -0,0 +1,19 @@
+-- An ELI5-ish (for 5 year old Haskell programmers, though if they are five year
+-- old and programming in Haskell, they might be able to explain me a thing or
+-- two) explanation of the most interesting, and the scariest, part of the
+-- solution to Day 5 Part 2 - calculating the splits.
+
+type Range = (Int, Int)
+
+splits :: Range -> Range -> [Range]
+splits (s, e) (s', e')
+  | s > e' = [(s, e)]
+  | e < s' = [(s, e)]
+  | s < s' = (s, s' - 1) : if e <= e' then [(s', e)] else [(s', e'), (e' + 1, e)]
+  | s <= e' = if e <= e' then [(s, e)] else [(s, e'), (e' + 1, e)]
+
+main :: IO ()
+main = do
+    print $ splits (1, 9) (10, 20)
+    print $ splits (1, 9) (7, 20)
+    print $ splits (1, 7) (7, 20)