Add single vertex contains method and replace vertices field with adjMatrix' keys

graph/graph.h

@@ -18,6 +18,9 @@ public:
   // Return true if e(u,v) exists
   virtual bool contains(const T& u, const T& v);
 
+  // Return true if vertex u exists
+  virtual bool contains(const T& u);
+
   // Remove edge e(u,v)
   virtual void remove(const T& u, const T& v);
 
@@ -31,20 +34,16 @@ public:
   virtual void output();
 
   // Adjacency matrix representation
-  std::set<T> vertices;
   std::map<T, std::set<T>> adjMatrix;
 };
 
 template<typename T>
 Graph<T>::~Graph() {
-  vertices.clear();
   adjMatrix.clear();
 }
 
 template<typename T>
 inline void Graph<T>::insert(const T& u, const T& v) {
-  Graph<T>::vertices.insert(u);
-  Graph<T>::vertices.insert(v);
   Graph<T>::adjMatrix[u].insert(v);
 }
 
@@ -53,6 +52,11 @@ bool Graph<T>::contains(const T& u, const T& v) {
   return adjMatrix[u].contains(v);
 }
 
+template<typename T>
+bool Graph<T>::contains(const T& u) {
+  return adjMatrix.contains(u);
+}
+
 template<typename T>
 void Graph<T>::remove(const T& u, const T& v) {
   adjMatrix[u].erase(v);
@@ -60,23 +64,23 @@ void Graph<T>::remove(const T& u, const T& v) {
 
 template<typename T>
 std::uint16_t Graph<T>::V() {
-  return static_cast<std::uint16_t>(vertices.size());
+  return static_cast<std::uint16_t>(adjMatrix.size());
 }
 
 template<typename T>
 std::uint16_t Graph<T>::E() {
   std::uint16_t edges = 0;
-  for (const auto& v : vertices) {
-    edges += static_cast<std::uint16_t>(adjMatrix[v].size());
+  for (const auto& v : adjMatrix) {
+    edges += static_cast<std::uint16_t>(v.second.size());
   }
   return static_cast<std::uint16_t>(edges);
 }
 
 template<typename T>
 void Graph<T>::output() {
-  for (const auto& v : vertices) {
-    for (const auto& u : adjMatrix[v]) {
-      std::cout << v << "->" << u << '|';
+  for (const auto& v : adjMatrix) {
+    for (const auto& u : v.second) {
+      std::cout << v.first << "->" << u << '|';
     }
     std::cout << '\n';
   }