public void UndirectGraphDeleteVertexTest()
{
UndirectGraph<int> graph = new UndirectGraph<int>();
graph.AddEdge(0, 1);
graph.AddEdge(2, 0);
graph.AddVertex(3);
graph.DeleteVertex(3);
graph.DeleteVertex(2);
string t1 = String.Format("{0} -> {1}{2}{1} -> {0}{2}", 0, 1, Environment.NewLine);
Assert.AreEqual(t1, graph.ToString());
graph.DeleteVertex(0);
graph.DeleteVertex(0);
string t2 = String.Format("{0}{1}", 1, Environment.NewLine);
Assert.AreEqual(t2, graph.ToString());
graph.DeleteVertex(1);
Assert.AreEqual("", graph.ToString());
Assert.AreEqual(0, graph.CountVertices);
Assert.AreEqual(0, graph.CountEdges);
}