aoc2024

commit 0d618af316e2b6af81063c5ec4d3763ffbfc2c14
parent 70032b46a6ca37ccb33527568acc5efa9765fad6
Author: Martin Ashby <martin@ashbysoft.com>
Date:   Mon,  9 Dec 2024 06:42:34 +0000

Day5 pt2

Diffstat:
M
src/main/scala/Day5.scala
 | 
22
++++++++++++++++++----
M
src/main/scala/Main.scala
 | 
4
++--

2 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/src/main/scala/Day5.scala b/src/main/scala/Day5.scala
@@ -1,4 +1,19 @@
 def day5_pt1(input: Iterator[String]): Int =
+    val (rules, updates) = parse_input(input)
+    updates
+        .filter(l => l.sliding(2).forall(ll => rules.contains((ll(0), ll(1)))))
+        .map(l => l(l.size / 2))
+        .sum
+
+def day5_pt2(input: Iterator[String]): Int =
+    val (rules, updates) = parse_input(input)
+    updates
+        .filter(l => !(l.sliding(2).forall(ll => rules.contains((ll(0), ll(1))))))
+        .map(lst => lst.sortWith((a, b) => rules.contains((a, b))))
+        .map(l => l(l.size / 2))
+        .sum
+
+def parse_input(input: Iterator[String]): (List[(Int,Int)], List[List[Int]]) =
     val lst = input.toList
     val ix = lst.indexOf("")
     val rulesStrs = lst.slice(0, ix)
@@ -7,7 +22,5 @@ def day5_pt1(input: Iterator[String]): Int =
         val a = s.split("\\|").map(ss => Integer.parseInt(ss))
         (a(0), a(1))
     })
-    updatesStrs.map(s => s.split(",").map(s => Integer.parseInt(s)).toList)
-        .filter(l => l.sliding(2).forall(ll => rules.contains((ll(0), ll(1)))))
-        .map(l => l(l.size / 2))
-        .sum
+    val updates = updatesStrs.map(s => s.split(",").map(s => Integer.parseInt(s)).toList)
+    return (rules, updates)
+\ No newline at end of file
diff --git a/src/main/scala/Main.scala b/src/main/scala/Main.scala
@@ -1,2 +1,2 @@
 @main def run(): Unit = 
-  println(day5_pt1(scala.io.Source.fromFile("day5.txt").getLines()))
-\ No newline at end of file
+  println(day5_pt2(scala.io.Source.fromFile("day5.txt").getLines()))
+\ No newline at end of file