public void UndirectedPathToFiveHasOneVertices()
{
var input = CreateTestInput();
var g = new Graph(GraphType.Undirected, input, 7);
var search = new Bfs(g, 0);
Assert.AreEqual(1, search.DistanceTo(5));
}
public void UndirectedPathToFiveHasTwoVertices()
{
var input = CreateTestInput();
var g = new Graph(GraphType.Undirected, input, 7);
var search = new Dfs(g, 0);
var path = search.PathTo(5).ToArray();
Assert.AreEqual(2, search.DistanceTo(5));
Assert.AreEqual(2, path[0]);
Assert.AreEqual(5, path[1]);
}
public void UndirectedConnectionsAreMarked()
{
var input = CreateTestInput();
var g = new Graph(GraphType.Undirected, input, 7);
var search = new Dfs(g, 0);
Assert.IsTrue(search.Marked(2));
Assert.IsTrue(search.Marked(3));
Assert.IsTrue(search.Marked(5));
Assert.IsFalse(search.Marked(1));
Assert.IsFalse(search.Marked(4));
Assert.IsFalse(search.Marked(6));
}
public Bfs(Graph graph, int root)
{
if (graph == null) {
throw new ArgumentNullException("graph");
}
this.marked = new bool[graph.Vertices()];
this.edgeTo = Enumerable.Repeat(-1, graph.Vertices()).ToArray();
this.distTo = Enumerable.Repeat(-1, graph.Vertices()).ToArray();
this.count = 0;
this.root = root;
this.BreadthFirstSearch(graph, root);
}
public void UndirectedHasPathToAreCorrect()
{
var input = CreateTestInput();
var g = new Graph(GraphType.Undirected, input, 7);
var search = new Dfs(g, 0);
Assert.IsTrue(search.HasPathTo(2));
Assert.IsTrue(search.HasPathTo(3));
Assert.IsTrue(search.HasPathTo(5));
Assert.IsFalse(search.HasPathTo(0)); // No path to self
Assert.IsFalse(search.HasPathTo(1));
Assert.IsFalse(search.HasPathTo(4));
Assert.IsFalse(search.HasPathTo(6));
}
public void UndirectedCreateIsCorrectlyBuilt()
{
var input = CreateTestInput();
var g = new Graph(GraphType.Undirected, input, 7);
Assert.AreEqual(7, g.Vertices());
Assert.AreEqual(10, g.Edges());
Assert.AreEqual(3, g.Adjacent(0).Count);
Assert.AreEqual(1, g.Adjacent(1).Count);
Assert.AreEqual(2, g.Adjacent(2).Count);
Assert.AreEqual(1, g.Adjacent(3).Count);
Assert.AreEqual(0, g.Adjacent(4).Count);
Assert.AreEqual(2, g.Adjacent(5).Count);
Assert.AreEqual(1, g.Adjacent(6).Count);
}
public void BreadthFirstSearch(Graph graph, int root)
{
var vertices = new Queue<int>();
vertices.Enqueue(root);
distTo[root] = 0;
marked[root] = true;
count++;
while (vertices.Count > 0) {
var currentVertice = vertices.Dequeue();
foreach (var vert in graph.Adjacent(currentVertice)) {
if (!marked[vert]) {
edgeTo[vert] = currentVertice;
distTo[vert] = distTo[currentVertice] + 1;
marked[vert] = true;
count++;
vertices.Enqueue(vert);
}
}
}
}
