public bool AddVertex(Vertex vertex)
{
try
{
vertexes.Add(vertex);
vertexEdgeMapping.Add(vertex, new LinkedList<Edge>());
return true;
}
catch (Exception e)
{
Console.WriteLine("Add vertex failed! {0}", e.Message);
return false;
}
}
public bool BreadthFirstSearch(Vertex rootVertex)
{
try
{
Console.WriteLine("******* Breadth First Search ********");
const string white = "white";
const string gray = "gray";
const string black = "black";
var colorMap = new Dictionary<Vertex, string>();
foreach (var vertex in vertexes)
{
colorMap.Add(vertex, white);
}
colorMap[rootVertex] = gray;
var queue = new Queue<Vertex>();
queue.Enqueue(rootVertex);
while (queue.Count != 0)
{
Vertex temp = queue.Dequeue();
foreach (Edge edge in vertexEdgeMapping[temp])
{
if (colorMap[edge.ToVertex] == white)
{
colorMap[edge.ToVertex] = gray;
queue.Enqueue(edge.ToVertex);
}
}
colorMap[temp] = black;
Console.WriteLine("Vertex {0} has been found!", temp.VertexLabel);
}
return true;
}
catch (Exception e)
{
Console.WriteLine("Breadth First Search failed! {0}", e.Message);
return false;
}
}
public bool AddEdge(Vertex from, Vertex to, int weight)
{
try
{
var newEdge = new Edge(from, to, weight);
vertexEdgeMapping[from].AddLast(newEdge);
if (IsDirectGraph == true)
{
var backEdge = new Edge(to, from, weight);
vertexEdgeMapping[to].AddLast(backEdge);
}
return true;
}
catch (Exception e)
{
Console.WriteLine("Add edge failed! {0}", e.Message);
return false;
}
}
public void Graph_Tests()
{
// Direct Graph
var G = new Graph(true);
var u = new Vertex("u");
var v = new Vertex("v");
var w = new Vertex("w");
var x = new Vertex("x");
var y = new Vertex("y");
var z = new Vertex("z");
// Add vertexes
G.AddVertex(u);
G.AddVertex(v);
G.AddVertex(w);
G.AddVertex(x);
G.AddVertex(y);
G.AddVertex(z);
// Add edges
G.AddEdge(u, v, 3);
G.AddEdge(u, x, 3);
G.AddEdge(v, y, 3);
G.AddEdge(w, y, 3);
G.AddEdge(w, z, 3);
G.AddEdge(x, v, 3);
G.AddEdge(y, x, 3);
G.AddEdge(z, u, 3);
//Depth Search First
G.DepthSearchFirst();
//Undirect Graph
var UG = new Graph(false);
var ur = new Vertex("r");
var us = new Vertex("s");
var ut = new Vertex("t");
var uu = new Vertex("u");
var uv = new Vertex("v");
var uw = new Vertex("w");
var ux = new Vertex("x");
var uy = new Vertex("y");
// Add vertexes
UG.AddVertex(ur);
UG.AddVertex(us);
UG.AddVertex(ut);
UG.AddVertex(uu);
UG.AddVertex(uv);
UG.AddVertex(uw);
UG.AddVertex(ux);
UG.AddVertex(uy);
// Add Edge
UG.AddEdge(ur, uv, 3);
UG.AddEdge(ur, us, 3);
UG.AddEdge(us, uw, 3);
UG.AddEdge(ut, uu, 3);
UG.AddEdge(ut, uw, 3);
UG.AddEdge(ut, ux, 3);
UG.AddEdge(uu, ux, 3);
UG.AddEdge(uu, uy, 3);
UG.AddEdge(uw, ux, 3);
UG.AddEdge(ux, uy, 3);
//Breadth First Search
UG.BreadthFirstSearch(us);
}
private bool DFS_Visit(Vertex vertex, Dictionary<Vertex, string> color)
{
try
{
const string white = "white";
const string gray = "gray";
const string black = "black";
color[vertex] = gray;
foreach (Edge edge in vertexEdgeMapping[vertex])
{
if (color[edge.ToVertex] == white)
{
DFS_Visit(edge.ToVertex, color);
}
}
color[vertex] = black;
Console.WriteLine("Vertex {0} has been found!", vertex.VertexLabel);
return true;
}
catch (Exception e)
{
Console.WriteLine("DFS_Visit failed! {0}", e.Message);
return false;
}
}