Use the renaming thing that they wanted

src/Tour.cpp

@@ -116,6 +116,48 @@ void Tour::insertNearest(Point p) {
     nearest->next = newNode;
 }
 
+Node *findbestNodeTSP(Node *const start, Point &point) {
+    auto calcHeuristic = [&point](Node *const insertAt) -> double {
+        double distanceWithNewPoint = insertAt->point.distanceTo(point) +
+                                      point.distanceTo(insertAt->next->point);
+        double originalDistance = insertAt->point.distanceTo(insertAt->next->point);
+
+        return distanceWithNewPoint - originalDistance;
+    };
+
+    double optimalH = Q_INFINITY;
+    Node *optimalNode;
+
+    Node *node = start;
+    do {
+        double h = calcHeuristic(node);
+        if (h < optimalH) {
+            optimalH = h;
+            optimalNode = node;
+        }
+        node = node->next;
+    } while (node != start);
+
+    return optimalNode;
+}
+
+void Tour::insertOptimalHeuristic(Point p) {
+    if (m_startNode == nullptr) {
+        m_startNode = new Node(p);
+        m_startNode->next = m_startNode; // Make it cirkular
+        return;
+    }
+    if (m_startNode->next == nullptr) {
+        auto newNode = new Node(p, m_startNode);
+        m_startNode->next = newNode;
+        return;
+    }
+
+    Node *bestNode = findbestNodeTSP(m_startNode, p);
+    auto *newNode = new Node(p, bestNode->next);
+    bestNode->next = newNode;
+}
+
 void Tour::insertSmallest(Point p) {
     if (m_startNode == nullptr) {
         m_startNode = new Node(p);

src/Tour.h

@@ -24,6 +24,7 @@ public:
     double distance() const;
     void insertNearest(Point p);
     void insertSmallest(Point p);
+    void insertOptimalHeuristic(Point p);
 
 private:
     Node* m_startNode;

src/tsp.cpp

@@ -49,7 +49,7 @@ int main(int argc, char *argv[]) {
     auto timeStart = std::chrono::high_resolution_clock::now();
     while (input >> x >> y) {
         Point p(x, y);
-        tour.insertNearest(p);
+        tour.insertOptimalHeuristic(p);
         //uncomment the 4 lines below to animate
         //tour.draw(scene);
         //std::chrono::milliseconds dura(50);