Add solution for "Day 6: Guard Gallivant", part 1

AdventOfCode2024/AdventOfCode2024.vcxproj

@@ -130,6 +130,7 @@
   <ItemGroup>
     <ClCompile Include="AdventOfCode2024.cpp" />
     <ClCompile Include="CeresSearch.cpp" />
+    <ClCompile Include="GuardGallivant.cpp" />
     <ClCompile Include="HistorianHysteria.cpp" />
     <ClCompile Include="LinesSolver.cpp" />
     <ClCompile Include="MullDataState.cpp" />
@@ -152,6 +153,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="CeresSearch.h" />
+    <ClInclude Include="GuardGallivant.h" />
     <ClInclude Include="HistorianHysteria.h" />
     <ClInclude Include="LinesSolver.h" />
     <ClInclude Include="MullDataState.h" />

AdventOfCode2024/AdventOfCode2024.vcxproj.filters

@@ -78,6 +78,9 @@
     <ClCompile Include="PrintQueue.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="GuardGallivant.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="SolverEngine.h">
@@ -146,5 +149,8 @@
     <ClInclude Include="PrintQueue.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="GuardGallivant.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

AdventOfCode2024/GuardGallivant.cpp

@@ -0,0 +1,91 @@
+// Solutions to the Advent Of Code 2024.
+// Copyright (C) 2024  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 "GuardGallivant.h"
+
+std::string GuardGallivant::getPuzzleName() const
+{
+    return "Day 6: Guard Gallivant";
+}
+
+std::string GuardGallivant::getInputFileName() const
+{
+    return "guard_gallivant.txt";
+}
+
+void GuardGallivant::processDataLine(const std::string& line)
+{
+    LinesSolver::processDataLine(line);
+    auto pos{ line.find(getStartChar()) };
+    if (pos != std::string::npos)
+    {
+        start_ = Point2{ static_cast<int>(pos), static_cast<int>(lines.size() - 1) };
+    }
+}
+
+void GuardGallivant::finish()
+{
+    auto dirIndex{ getStartDirectionIndex() };
+    auto current{ start_ };
+    visitPosition(current);
+    auto next{ current + Point2::cardinalDirections[dirIndex] };
+    while (isInBounds(next))
+    {
+        if (getPosition(next) == getObstructionChar())
+        {
+            dirIndex = turnDirection(dirIndex);
+        }
+        else
+        {
+            current = next;
+            visitPosition(current);
+        }
+        next = current + Point2::cardinalDirections[dirIndex];
+    }
+}
+
+void GuardGallivant::visitPosition(const Point2& current)
+{
+    if (getPosition(current) != getVisitedChar())
+    {
+        setPosition(current, getVisitedChar());
+        part1++;
+    }
+}
+
+size_t GuardGallivant::turnDirection(const size_t current) const
+{
+    return current == 0 ? 3 : current - 1;
+}
+
+size_t GuardGallivant::getStartDirectionIndex() const
+{
+    return 2;
+}
+
+char GuardGallivant::getStartChar() const
+{
+    return '^';
+}
+
+char GuardGallivant::getVisitedChar() const
+{
+    return 'X';
+}
+
+char GuardGallivant::getObstructionChar() const
+{
+    return '#';
+}

AdventOfCode2024/GuardGallivant.h

@@ -0,0 +1,35 @@
+// Solutions to the Advent Of Code 2024.
+// Copyright (C) 2024  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 "LinesSolver.h"
+
+class GuardGallivant :
+    public LinesSolver
+{
+public:
+    Point2 start_{};
+    std::string getPuzzleName() const override;
+    std::string getInputFileName() const override;
+    void processDataLine(const std::string& line) override;
+    void finish() override;
+    void visitPosition(const Point2& current);
+    size_t turnDirection(const size_t current) const;
+    size_t getStartDirectionIndex() const;
+    char getStartChar() const;
+    char getVisitedChar() const;
+    char getObstructionChar() const;
+};

AdventOfCode2024/LinesSolver.cpp

@@ -20,13 +20,18 @@ void LinesSolver::processDataLine(const std::string& line)
     lines.push_back(line);
 }
 
-bool LinesSolver::isInBounds(const Point2& point)
+bool LinesSolver::isInBounds(const Point2& point) const
 {
     return 0 <= point.y && point.y < lines.size()
         && 0 <= point.x && point.x < lines[point.y].size();
 }
 
-char LinesSolver::getPosition(const Point2& point)
+char LinesSolver::getPosition(const Point2& point) const
 {
     return lines[point.y][point.x];
 }
+
+void LinesSolver::setPosition(const Point2& point, const char value)
+{
+    lines[point.y][point.x] = value;
+}

AdventOfCode2024/LinesSolver.h

@@ -27,6 +27,7 @@ class LinesSolver :
     void processDataLine(const std::string& line) override;
 protected:
     std::vector<std::string> lines{};
-    bool isInBounds(const Point2& point);
+    bool isInBounds(const Point2& point) const;
-    char getPosition(const Point2& point);
+    char getPosition(const Point2& point) const;
+    void setPosition(const Point2& point, const char value);
 };

AdventOfCode2024/Point2.cpp

@@ -23,8 +23,10 @@ const Point2 Point2::upLeft{ -1, -1 };
 const Point2 Point2::upRight{ 1, -1 };
 const Point2 Point2::downLeft{ -1, 1 };
 const Point2 Point2::downRight{ 1, 1 };
-const Point2 Point2::directions[] = { Point2::left, Point2::right, Point2::up, Point2::down,
+const Point2 Point2::directions[] = { Point2::down, Point2::downRight, Point2::right,
-    Point2::upLeft, Point2::upRight, Point2::downLeft, Point2::downRight };
+    Point2::upRight, Point2::up, Point2::upLeft, Point2::left, Point2::downLeft };
+const Point2 Point2::cardinalDirections[] = { Point2::down, Point2::right, Point2::up,
+    Point2::left};
 
 Point2::Point2()
     : Point2{ 0, 0 } {}

AdventOfCode2024/Point2.h

@@ -20,7 +20,15 @@ class Point2
 public:
     static const Point2 left, right, up, down;
     static const Point2 upLeft, upRight, downLeft, downRight;
+    /// <summary>
+    /// The eight cardinal and diagonal directions starting down, rotating in
+    /// positive direction.
+    /// </summary>
     static const Point2 directions[8];
+    /// <summary>
+    /// The four cardinal directions starting down, rotating in positive direction.
+    /// </summary>
+    static const Point2 cardinalDirections[4];
     int x, y;
     Point2();
     Point2(const int x, const int y);

AdventOfCode2024/Program.cpp

@@ -25,6 +25,7 @@
 #include "MullItOver.h"
 #include "CeresSearch.h"
 #include "PrintQueue.h"
+#include "GuardGallivant.h"
 
 void Program::run()
 {
@@ -40,6 +41,7 @@ void Program::runSolvers()
     solverEngine.run(*std::make_unique<MullItOver>());
     solverEngine.run(*std::make_unique<CeresSearch>());
     solverEngine.run(*std::make_unique<PrintQueue>());
+    solverEngine.run(*std::make_unique<GuardGallivant>());
 }
 
 std::vector<std::string> Program::getInputPaths() const