Add solution for "Day 12: Garden Groups", part 1

include/aoc/GardenGroups.hpp

@@ -0,0 +1,33 @@
+// Solutions to the Advent Of Code 2024.
+// Copyright (C) 2025  Stefan Müller
+//
+// This program is free software: you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation, either version 3 of the License, or (at your option) any later
+// version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <stack>
+
+#include <aoc/Grid.hpp>
+#include <aoc/LinesSolver.hpp>
+#include <aoc/Point2.hpp>
+
+class GardenGroups
+    : public LinesSolver
+{
+public:
+    virtual const std::string getPuzzleName() const override;
+    virtual const std::string getInputFileName() const override;
+    virtual void finish() override;
+private:
+    void traverseRegion(Grid<bool>& isVisited, std::stack<Point2>& otherRegionsStack, const Point2& start);
+};