diff --git a/include/aoc/ReindeerMaze.hpp b/include/aoc/ReindeerMaze.hpp
index 1e533a4..a5f3400 100644
--- a/include/aoc/ReindeerMaze.hpp
+++ b/include/aoc/ReindeerMaze.hpp
@@ -36,6 +36,7 @@ class ReindeerMaze
     static constexpr char getEndChar();
     static constexpr char getWallChar();
     static constexpr int getTurnCost();
+    void buildPathSegmentGraph(WeightedEdgeGraph& graph, const int entry, const int exit);
     void initializeWorkList(std::list<ReindeerMazeCrossing>& crossings, const int entryVertex);
     void addCheckedIncidence(std::vector<ReindeerMazePathIncidence>& incidences, const Point2 start,
         const Point2 direction);
diff --git a/src/ReindeerMaze.cpp b/src/ReindeerMaze.cpp
index de2aeb5..ede32ba 100644
--- a/src/ReindeerMaze.cpp
+++ b/src/ReindeerMaze.cpp
@@ -32,11 +32,38 @@ const int ReindeerMaze::getPuzzleDay() const
 
 void ReindeerMaze::finish()
 {
-    // Initializes the graph of path segment incidences.
     WeightedEdgeGraph graph{};
     auto entry = graph.addVertex();
     auto exit = graph.addVertex();
+    buildPathSegmentGraph(graph, entry, exit);
 
+    part1 = graph.dijkstra(entry, exit) / 2;
+}
+
+constexpr char ReindeerMaze::getStartChar()
+{
+    return 'S';
+}
+
+constexpr char ReindeerMaze::getEndChar()
+{
+    return 'E';
+}
+
+constexpr char ReindeerMaze::getWallChar()
+{
+    return '#';
+}
+
+constexpr int ReindeerMaze::getTurnCost()
+{
+    return 1000;
+}
+
+// Constructs the graph of path segment incidences, starting with a graph that already contains the entry and the exit
+// vertices.
+void ReindeerMaze::buildPathSegmentGraph(WeightedEdgeGraph& graph, const int entry, const int exit)
+{
     // Uses list for work items to prevent invalidation of iterators on add.
     std::list<ReindeerMazeCrossing> crossings{};
     initializeWorkList(crossings, entry);
@@ -56,8 +83,8 @@ void ReindeerMaze::finish()
 
         int nNext{ 0 };
         while (getCharAt(position) != getEndChar() &&
-            std::find_if(crossings.begin(), crossings.end(),
-                [position](auto& x) { return x.getPosition() == position; }) == crossings.end())
+               std::find_if(crossings.begin(), crossings.end(),
+                   [position](auto& x) { return x.getPosition() == position; }) == crossings.end())
         {
             nNext = 0;
             Point2 nextPosition, nextDirection;
@@ -143,10 +170,9 @@ void ReindeerMaze::finish()
             // Determines the end crossing of the new path segment and its incidence.
             std::list<ReindeerMazeCrossing>::iterator endCrossing;
             std::vector<ReindeerMazePathIncidence>::iterator endIncidence;
-            endCrossing = nNext == 1
-                ? endCrossing = std::find_if(crossings.begin(), crossings.end(),
-                    [position](auto& x) { return x.getPosition() == position; })
-                : --crossings.end();
+            endCrossing = nNext == 1 ? endCrossing = std::find_if(crossings.begin(), crossings.end(),
+                                           [position](auto& x) { return x.getPosition() == position; })
+                                     : --crossings.end();
             if (endCrossing != crossings.end())
             {
                 // This incidence must exist, no need to check the incidence iterator.
@@ -168,7 +194,7 @@ void ReindeerMaze::finish()
             }
 
             // Checks if end crossing is finished.
-            //checkFinishedCrossing(crossings, endCrossing);
+            // checkFinishedCrossing(crossings, endCrossing);
             if (endCrossing != crossings.end() && endCrossing->isFinished())
             {
                 crossings.erase(endCrossing);
@@ -181,28 +207,6 @@ void ReindeerMaze::finish()
             crossings.erase(startCrossing);
         }
     }
-
-    part1 = graph.dijkstra(entry, exit) / 2;
-}
-
-constexpr char ReindeerMaze::getStartChar()
-{
-    return 'S';
-}
-
-constexpr char ReindeerMaze::getEndChar()
-{
-    return 'E';
-}
-
-constexpr char ReindeerMaze::getWallChar()
-{
-    return '#';
-}
-
-constexpr int ReindeerMaze::getTurnCost()
-{
-    return 1000;
 }
 
 // Initializes the work list of crossing incidences.