From a467472e836b142f5ce9277a0b01317968a3192e Mon Sep 17 00:00:00 2001
From: Xavier Morel <morelx42@gmail.com>
Date: Tue, 4 Dec 2018 18:01:49 +0100
Subject: [PATCH] Adding day 1

---
 day1/part1.scala | 12 ++++++++++++
 day1/part2.scala | 23 +++++++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 day1/part1.scala
 create mode 100644 day1/part2.scala

diff --git a/day1/part1.scala b/day1/part1.scala
new file mode 100644
index 0000000..ac5496f
--- /dev/null
+++ b/day1/part1.scala
@@ -0,0 +1,12 @@
+/**
+ * Usage: scala part1.scala < input
+ */
+
+import scala.io.StdIn
+import scala.collection.Iterator
+
+println(Iterator
+  .continually(StdIn.readLine)
+  .takeWhile(_ != null)
+  .map(Integer.parseInt)
+  .sum)
diff --git a/day1/part2.scala b/day1/part2.scala
new file mode 100644
index 0000000..bab57ee
--- /dev/null
+++ b/day1/part2.scala
@@ -0,0 +1,23 @@
+/**
+ * Usage: scala part2.scala < input
+ */
+
+import scala.io.StdIn
+import scala.collection.Iterator
+
+val items = Stream
+  .continually(StdIn.readLine)
+  .takeWhile(_ != null)
+  .map(Integer.parseInt)
+  .toList
+
+println(
+Stream
+  .continually(items.toStream)
+  .flatten
+  .scanLeft(0)(_ + _)
+  .scanLeft(Map.empty[Int, Int]){case (acc, item) => acc + (item -> (acc.getOrElse(item, 0) + 1)) }
+  .filter(_.count(_._2 == 2) > 0)
+  .map(_.maxBy(_._2))
+  .head
+)