From ff454776fab77299932290f76c86cc20db7748fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20M=C3=BCller?= <stefan.mueller@aksdb.de>
Date: Sun, 22 Dec 2024 22:59:38 +0100
Subject: [PATCH] Add solution for "Day 10: Hoof It", part 2

---
 src/HoofIt.cpp | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/HoofIt.cpp b/src/HoofIt.cpp
index acec2d2..011c1ab 100644
--- a/src/HoofIt.cpp
+++ b/src/HoofIt.cpp
@@ -34,22 +34,28 @@ std::string HoofIt::getInputFileName() const
 void HoofIt::finish()
 {
     std::queue<Point2> queue{};
-    std::vector<std::vector<std::vector<Point2>>> trailScoreMap{};
+    std::vector<std::vector<std::vector<Point2>>> trailEndsMap{};
+    trailEndsMap.reserve(lines.size());
+    std::vector<std::vector<int>> trailScoreMap{};
     trailScoreMap.reserve(lines.size());
 
     for (int j = 0; j < lines.size(); j++)
     {
-        std::vector<std::vector<Point2>> row{};
-        row.reserve(lines[j].size());
-        trailScoreMap.push_back(row);
+        std::vector<std::vector<Point2>> endsRow{};
+        endsRow.reserve(lines[j].size());
+        trailEndsMap.push_back(endsRow);
+        std::vector<int> scoreRow(lines[j].size(), 0);
+        trailScoreMap.push_back(scoreRow);
+
         for (int i = 0; i < lines[j].size(); i++)
         {
             std::vector<Point2> ends{};
-            trailScoreMap[j].push_back(ends);
+            trailEndsMap[j].push_back(ends);
             if (lines[j][i] == getTrailTopChar())
             {
                 Point2 trailEnd{ i, j };
-                trailScoreMap[j][i].push_back(trailEnd);
+                trailEndsMap[j][i].push_back(trailEnd);
+                trailScoreMap[j][i] = 1;
                 queue.push(trailEnd);
             }
         }
@@ -66,17 +72,19 @@ void HoofIt::finish()
                 Point2 p{ trail + direction };
                 if (isInBounds(p) && getPosition(p) + 1 == getPosition(trail))
                 {
-                    if (trailScoreMap[p.y][p.x].empty())
+                    if (trailEndsMap[p.y][p.x].empty())
                     {
                         queue.push(p);
                     }
-                    addUnique(trailScoreMap[trail.y][trail.x], trailScoreMap[p.y][p.x]);
+                    addUnique(trailEndsMap[trail.y][trail.x], trailEndsMap[p.y][p.x]);
+                    trailScoreMap[p.y][p.x] += trailScoreMap[trail.y][trail.x];
                 }
             }
         }
         else
         {
-            part1 += trailScoreMap[trail.y][trail.x].size();
+            part1 += trailEndsMap[trail.y][trail.x].size();
+            part2 += trailScoreMap[trail.y][trail.x];
         }
     }
 }