Add solution for "Day 18: RAM Run", part 1

src/Program.cpp

@@ -38,6 +38,7 @@
 #include <aoc/WarehouseWoes.hpp>
 #include <aoc/ReindeerMaze.hpp>
 #include <aoc/ChronospatialComputer.hpp>
+#include <aoc/RamRun.hpp>
 #include <aoc/LanParty.hpp>
 
 void Program::run()
@@ -73,6 +74,7 @@ void Program::runSolvers()
     runSolver<WarehouseWoes>(solverEngine);
     runSolver<ReindeerMaze>(solverEngine);
     runSolver<ChronospatialComputer>(solverEngine);
+    runSolver<RamRun>(solverEngine);
     runSolver<LanParty>(solverEngine);
 }
 

src/RamRun.cpp

@@ -0,0 +1,107 @@
+// 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/>.
+
+#include <aoc/RamRun.hpp>
+
+#include <sstream>
+
+RamRun::RamRun(const size_t memorySize, const int maxBytes)
+    : memorySize_{ memorySize }, maxBytes_{ maxBytes }, nBytes_{ 0 }, vertexReferences_{ memorySize, memorySize }
+{
+    vertexReferences_.fill(getUnknownVertexReference());
+}
+
+const std::string RamRun::getPuzzleName() const
+{
+    return "RAM Run";
+}
+
+const int RamRun::getPuzzleDay() const
+{
+    return 18;
+}
+
+void RamRun::processDataLine(const std::string& line)
+{
+    if (maxBytes_ > nBytes_++)
+    {
+        std::istringstream stream{ line };
+        Point2 position;
+        char c;
+        if (stream >> position.x >> c >> position.y)
+        {
+            vertexReferences_.cell(position) = getNoVertexReference();
+        }
+
+        if (maxBytes_ == nBytes_)
+        {
+            WeightedEdgeGraph graph{};
+            buildGraph(graph);
+            auto distances = graph.dijkstra(vertexReferences_[0][0]);
+            part1 = distances[vertexReferences_[memorySize_ - 1][memorySize_ - 1]];
+        }
+    }
+}
+
+void RamRun::finish()
+{
+}
+
+constexpr char RamRun::getUnknownVertexReference()
+{
+    return -1;
+}
+
+constexpr char RamRun::getNoVertexReference()
+{
+    return -2;
+}
+
+void RamRun::buildGraph(WeightedEdgeGraph& graph)
+{
+    for (size_t j = 0; j < vertexReferences_.getNRows(); j++)
+    {
+        for (size_t i = 0; i < vertexReferences_.getNColumns(); i++)
+        {
+            if (vertexReferences_[j][i] != getNoVertexReference())
+            {
+                int v{ getVertex(graph, i, j) };
+                if (i != 0)
+                {
+                    if (vertexReferences_[j][i - 1] != getNoVertexReference())
+                    {
+                        graph.addEdge(getVertex(graph, i - 1, j), v, 1);
+                    }
+                }
+                if (j != 0)
+                {
+                    if (vertexReferences_[j - 1][i] != getNoVertexReference())
+                    {
+                        graph.addEdge(getVertex(graph, i, j - 1), v, 1);
+                    }
+                }
+            }
+        }
+    }
+}
+
+int RamRun::getVertex(WeightedEdgeGraph& graph, const size_t x, const size_t y)
+{
+    if (vertexReferences_[y][x] == getUnknownVertexReference())
+    {
+        vertexReferences_[y][x] = graph.addVertex();
+    }
+    return vertexReferences_[y][x];
+}