public BreadthFirstSearch(DiGraph g, int s)
{
nodes = new VertexNode[g.V];
for (int i = 0; i < nodes.Length; i++)
{
nodes[i] = new VertexNode(i);
nodes[i].Color = VertexColor.White;
}
bfs(g, s);
}
private void dfs(DiGraph g, int v)
{
marked[v] = true;
sc.Last().Add(v);
foreach (int w in g.Adj(v))
{
if (!marked[w])
{
dfs(g, w);
}
}
}
/// <summary>
/// the reverse version
/// </summary>
/// <returns></returns>
public DiGraph Reverse()
{
DiGraph graph = new DiGraph(v);
for (int i = 0; i < adjs.Length; i++)
{
for (int j = 0; j < adjs[i].Count; j++)
{
graph.AddEdge(adjs[i][j], i);
}
}
return(graph);
}
public DepthFirstSearch(DiGraph g, int s)
{
nodes = new VertexNode[g.V];
preOrder = new Queue <int>();
postOrder = new Queue <int>();
for (int i = 0; i < nodes.Length; i++)
{
nodes[i] = new VertexNode(i);
nodes[i].Color = VertexColor.White;
}
nodes[s].Distance = 0;
dfs(g, s);
}
private void dfs(DiGraph g, int s)
{
nodes[s].Color = VertexColor.Gray;
nodes[s].Discovered = ++time;
foreach (int w in g.Adj(s))
{
if (nodes[w].Color == VertexColor.White)
{
nodes[w].Parent = nodes[s];
dfs(g, w);
}
}
nodes[s].Color = VertexColor.Black;
nodes[s].Finished = ++time;
postOrder.Enqueue(s);
}
public StrongConnected(DiGraph g)
{
DepthFirstSearchs dfo = new DepthFirstSearchs(g);
marked = new bool[g.V];
sc = new List <HashSet <int> >();
g = g.Reverse();
foreach (int v in dfo.ReversePostOrder())
{
if (!marked[v])
{
sc.Add(new HashSet <int>());
dfs(g, v);
}
}
}
public TopologicalSort(DiGraph g)
{
postOrder = new Queue <int>();
nodes = new VertexNode[g.V];
for (int i = 0; i < nodes.Length; i++)
{
nodes[i] = new VertexNode(i);
nodes[i].Color = VertexColor.White;
}
for (int i = 0; i < g.V; i++)
{
if (nodes[i].Color == VertexColor.White)
{
dfs(g, i);
}
}
}
public DepthFirstSearchs(DiGraph g)
{
preOrder = new Queue <int>();
postOrder = new Queue <int>();
nodes = new VertexNode[g.V];
for (int i = 0; i < nodes.Length; i++)
{
nodes[i] = new VertexNode(i);
nodes[i].Color = VertexColor.White;
}
for (int i = 0; i < nodes.Length; i++)
{
if (nodes[i].Color == VertexColor.White)
{
dfs(g, i);
}
}
}
private void bfs(DiGraph g, int s)
{
nodes[s].Parent = null;
nodes[s].Distance = 0;
nodes[s].Color = VertexColor.Gray;
Queue <int> queue = new Queue <int>();
queue.Enqueue(s);
while (queue.Count != 0)
{
int u = queue.Dequeue();
foreach (var v in g.Adj(u))
{
if (nodes[v].Color == VertexColor.White)
{
nodes[v].Color = VertexColor.Gray;
nodes[v].Distance = nodes[u].Distance + 1;
nodes[v].Parent = nodes[u];
queue.Enqueue(v);
}
}
nodes[u].Color = VertexColor.Black;
}
}
