public void CreateEmptyGraphAndAddVertices()
{
var graph = new UndirectedGraph();
Assert.AreEqual(0, graph.Vertices());
Assert.AreEqual(0, graph.Edges());
int vertex1id = graph.AddVertex();
int vertex2id = graph.AddVertex();
Assert.AreEqual(0, vertex1id);
Assert.AreEqual(1, vertex2id);
graph.AddEdge(0, 1);
Assert.AreEqual(2, graph.Vertices());
Assert.AreEqual(1, graph.Edges());
Assert.IsTrue(graph.AdjacentVertices(0).Contains(1));
Assert.IsTrue(graph.AdjacentVertices(1).Contains(0));
// add the same edge again
graph.AddEdge(0, 1);
Assert.AreEqual(2, graph.Vertices());
Assert.AreEqual(2, graph.Edges());
Assert.IsTrue(graph.AdjacentVertices(0).Contains(1));
Assert.IsTrue(graph.AdjacentVertices(1).Contains(0));
}
public void CreateGraphWithSelfLoops()
{
var graph = new UndirectedGraph(1);
Assert.AreEqual(1, graph.Vertices());
Assert.AreEqual(0, graph.Edges());
graph.AddEdge(0, 0);
Assert.AreEqual(1, graph.Edges());
Assert.IsTrue(graph.AdjacentVertices(0).Contains(0));
}
public void CreateGraphWithPresetAmountOfVertices()
{
// a cube
var graph = new UndirectedGraph(4);
graph.AddEdge(0, 1);
graph.AddEdge(1, 2);
graph.AddEdge(2, 3);
graph.AddEdge(3, 0);
Assert.AreEqual(4, graph.Vertices());
Assert.AreEqual(4, graph.Edges());
Assert.IsTrue(graph.AdjacentVertices(0).Contains(1));
Assert.IsTrue(graph.AdjacentVertices(0).Contains(3));
Assert.IsTrue(graph.AdjacentVertices(1).Contains(0));
Assert.IsTrue(graph.AdjacentVertices(1).Contains(2));
Assert.IsTrue(graph.AdjacentVertices(2).Contains(1));
Assert.IsTrue(graph.AdjacentVertices(2).Contains(3));
Assert.IsTrue(graph.AdjacentVertices(3).Contains(2));
Assert.IsTrue(graph.AdjacentVertices(3).Contains(0));
}