From 725fa439d4543c140924097ce119f9dd234f4754 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20Zaicsek?= <zebalu@gmail.com>
Date: Sun, 17 Dec 2023 09:09:30 +0100
Subject: [PATCH] :( real solution to day 17 :'(

so it turns out I was just lucky :(

There is a requirement: *the ultra cart must go _at least 4 blocks_
before it can turn _or stop_* I was not filtering for this, but my
solution was working for the input anyways.

Reading discussions on reddit made me realize, I should add 1 more tests
to my solution. I am sad now...
---
 .../main/java/io/github/zebalu/aoc2023/days/Day17.java    | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/aoc2023/src/main/java/io/github/zebalu/aoc2023/days/Day17.java b/aoc2023/src/main/java/io/github/zebalu/aoc2023/days/Day17.java
index d4fbbac..f2c188f 100644
--- a/aoc2023/src/main/java/io/github/zebalu/aoc2023/days/Day17.java
+++ b/aoc2023/src/main/java/io/github/zebalu/aoc2023/days/Day17.java
@@ -12,14 +12,14 @@ public static void main(String[] args) {
     }
 
     private static int part1(List<String> maze) {
-        return minHeatLoss(maze, 3, (a, b) -> true);
+        return minHeatLoss(maze, 3, (a, b) -> true, i -> true);
     }
 
     private static int part2(List<String> maze) {
-        return minHeatLoss(maze, 10, (c, s) -> 4 <= s.straightLength() || s.pos().directionOf(c) == s.dir());
+        return minHeatLoss(maze, 10, (c, s) -> 4 <= s.straightLength() || s.pos().directionOf(c) == s.dir(), i -> 4<= i);
     }
 
-    private static int minHeatLoss(List<String> maze, int maxLength, BiPredicate<Coord, State> nextFilter) {
+    private static int minHeatLoss(List<String> maze, int maxLength, BiPredicate<Coord, State> nextFilter, Predicate<Integer> stopFilter) {
         int height = maze.size();
         int width = maze.getFirst().length();
         Predicate<Coord> isValidCood = c -> 0 <= c.x() && 0 <= c.y() && c.x < width && c.y < height;
@@ -36,7 +36,7 @@ private static int minHeatLoss(List<String> maze, int maxLength, BiPredicate<Coo
                             curr.nextStraight(c), curr.heatLoss() + heatCost(c, maze), curr.pos().directionOf(c)))
                     .filter(isValidState).toList();
             for (State s : nextStates) {
-                if (s.pos().equals(target)) {
+                if (s.pos().equals(target) && stopFilter.test(s.straightLength())) {
                     return s.heatLoss;
                 }
                 var costKey = s.toKey();