From 018d194796c85a5b4e665f2668c984dbac7b8537 Mon Sep 17 00:00:00 2001
From: qvalentin <valentin.theodor@web.de>
Date: Sat, 10 Dec 2022 18:50:02 +0100
Subject: [PATCH] start with three

---
 .gitignore |  1 +
 three.hs   | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 three.hs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..0721bc5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+!*.hs
diff --git a/three.hs b/three.hs
new file mode 100644
index 0000000..dcc0e05
--- /dev/null
+++ b/three.hs
@@ -0,0 +1,15 @@
+
+splitlist :: [a] -> ([a],[a])
+splitlist list = (take n list,drop n list)
+  where n = (length list) `div` 2
+
+inBoth :: (Eq a) => ([a],[a]) -> [a]
+inBoth (first,second) = do
+  inFirst <- first
+  if (inFirst `elem` second) then return inFirst else []
+
+
+
+main = do
+  input <- readFile "three-input.txt"
+  print $ map ( inBoth . splitlist ) $ lines input