Recalculation if graph was changed

bonewell · Jun 27, 2020 · 8f2f707 · 8f2f707
1 parent ebb1dba
commit 8f2f707
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Showing 3 changed files with 54 additions and 1 deletion.
diff --git a/graph.cpp b/graph.cpp
@@ -58,6 +58,7 @@ void Graph::calculate(Vertex& from) {
     updateNeighbors(current);
     markAsVisited(current);
   } while (!isFinished());
+  dirty_ = false;
 }
 
 void Graph::init() {
@@ -83,6 +84,7 @@ Id Graph::addVertex() {
 void Graph::setEdge(Id from, Id to, Distance distance) {
   checkDistance(distance);
   at(from)->neighbors[at(to)] = distance;
+  dirty_ = true;
 }
 
 std::list<Id> Graph::path(Vertex const& to) const {
@@ -98,7 +100,7 @@ std::list<Id> Graph::path(Vertex const& to) const {
 std::list<Id> Graph::path(Id from, Id to, bool force) {
   auto& source = *at(from);
   auto const& target = *at(to);
-  if (force || !source.isSource()) {
+  if (force || dirty_ || !source.isSource()) {
     calculate(source);
   }
   return path(target);
@@ -114,6 +116,7 @@ Vertex* Graph::at(Id id) {
 
 void Graph::removeEdge(Id from, Id to) {
   at(from)->neighbors.erase(at(to));
+  dirty_ = true;
 }
 
 void Graph::removeVertex(Id id) {
@@ -122,6 +125,7 @@ void Graph::removeVertex(Id id) {
     p.second.neighbors.erase(v);
   });
   vertexes_.erase(v->id);
+  dirty_ = true;
 }
 
 void Graph::checkDistance(Distance distance) const {

diff --git a/graph.h b/graph.h
@@ -145,6 +145,7 @@ class Graph {
   Id id_{0};
   std::unordered_map<Id, Vertex> vertexes_;
   std::set<Vertex*, LessDistance> unvisited_{LessDistance{}};
+  bool dirty_{true};
 };
 
 #endif /* GRAPH_H_ */
diff --git a/graph_test.cpp b/graph_test.cpp
@@ -319,3 +319,51 @@ TEST(SPF, CalculatedTwoDifferentPathes) {
 
   EXPECT_THAT(g.path(0, 4), ContainerEq(std::list<Id>{0, 2, 5, 4}));
 }
+
+TEST(SPF, RecalculateIfEdgeRemoved) {
+  Graph g;
+  g.addVertex(); g.addVertex(); g.addVertex(); g.addVertex();
+  g.addVertex(); g.addVertex();
+  g.setEdge(0, 1, 7); g.setEdge(0, 2, 9); g.setEdge(0, 5, 14);
+  g.setEdge(1, 0, 7); g.setEdge(1, 2, 10); g.setEdge(1, 3, 15);
+  g.setEdge(2, 0, 9); g.setEdge(2, 1, 10); g.setEdge(2, 5, 2);
+  g.setEdge(3, 1, 15); g.setEdge(3, 2, 11); g.setEdge(3, 4, 6);
+  g.setEdge(4, 3, 6); g.setEdge(4, 5, 9);
+  g.setEdge(5, 0, 14); g.setEdge(5, 2, 2); g.setEdge(5, 4, 9);
+  g.path(0, 4);
+  g.removeEdge(2, 5);
+
+  EXPECT_THAT(g.path(0, 4), ContainerEq(std::list<Id>{0, 5, 4}));
+}
+
+TEST(SPF, RecalculateIfWeightUpdated) {
+  Graph g;
+  g.addVertex(); g.addVertex(); g.addVertex(); g.addVertex();
+  g.addVertex(); g.addVertex();
+  g.setEdge(0, 1, 7); g.setEdge(0, 2, 9); g.setEdge(0, 5, 14);
+  g.setEdge(1, 0, 7); g.setEdge(1, 2, 10); g.setEdge(1, 3, 15);
+  g.setEdge(2, 0, 9); g.setEdge(2, 1, 10); g.setEdge(2, 5, 2);
+  g.setEdge(3, 1, 15); g.setEdge(3, 2, 11); g.setEdge(3, 4, 6);
+  g.setEdge(4, 3, 6); g.setEdge(4, 5, 9);
+  g.setEdge(5, 0, 14); g.setEdge(5, 2, 2); g.setEdge(5, 4, 9);
+  g.path(1, 5);
+  g.setEdge(2, 5, 100);
+
+  EXPECT_THAT(g.path(0, 4), ContainerEq(std::list<Id>{0, 5, 4}));
+}
+
+TEST(SPF, RecalculateIfVertexRemoved) {
+  Graph g;
+  g.addVertex(); g.addVertex(); g.addVertex(); g.addVertex();
+  g.addVertex(); g.addVertex();
+  g.setEdge(0, 1, 7); g.setEdge(0, 2, 9); g.setEdge(0, 5, 14);
+  g.setEdge(1, 0, 7); g.setEdge(1, 2, 10); g.setEdge(1, 3, 15);
+  g.setEdge(2, 0, 9); g.setEdge(2, 1, 10); g.setEdge(2, 5, 2);
+  g.setEdge(3, 1, 15); g.setEdge(3, 2, 11); g.setEdge(3, 4, 6);
+  g.setEdge(4, 3, 6); g.setEdge(4, 5, 9);
+  g.setEdge(5, 0, 14); g.setEdge(5, 2, 2); g.setEdge(5, 4, 9);
+  g.path(1, 5);
+  g.removeVertex(2);
+
+  EXPECT_THAT(g.path(0, 4), ContainerEq(std::list<Id>{0, 5, 4}));
+}