public DirectedDFS(Digraph G, int s)
{
marked = new bool[G.V];
edgeTo = new int[G.V];
this.s = s;
DFS(G, s);
}
public DirectedBFS(Digraph G, IEnumerable<int> sources)
{
marked = new bool[G.V];
edgeTo = new int[G.V];
this.s = new HashSet<int>(sources);
BFS(G, s);
}
private void DFS(Digraph G, int v)
{
marked[v] = true;
id[v] = count;
foreach (var w in G.Adj(v))
if (!marked[w])
DFS(G, w);
}
public DirectedBFS(Digraph G, int source)
{
marked = new bool[G.V];
edgeTo = new int[G.V];
this.s = new HashSet<int>();
s.Add(source);
BFS(G, s);
}
public DepthFirstOrder(Digraph G)
{
reversePost = new Stack<int>();
marked = new bool[G.V];
for (int v = 0; v < G.V; v++)
if (!marked[v])
DFS(G, v);
}
private void DFS(Digraph G, int v)
{
marked[v] = true;
foreach (var w in G.Adj(v))
{
if (!marked[w]) DFS(G,w);
}
reversePost.Push(v);
}
private void DFS(Digraph G, int v)
{
marked[v] = true;
foreach (var w in G.Adj(v))
{
if (!marked[w])
{
DFS(G, w);
edgeTo[w] = v;
}
}
}
public SCC_KosarajuSharir(Digraph G)
{
marked = new bool[G.V];
id = new int[G.V];
DepthFirstOrder dfs = new DepthFirstOrder(G.Reverse());
foreach (int v in dfs.GetReversePost())
{
if (!marked[v])
{
DFS(G, v);
count++;
}
}
}
private void BFS(Digraph G, IEnumerable<int> sources)
{
Queue<int> q = new Queue<int>();
foreach (int source in sources)
{
q.Enqueue(source);
}
while (!(q.Count == 0))
{
int v = q.Dequeue();
foreach (int w in G.Adj(v))
{
if (!marked[w])
{
q.Enqueue(w);
marked[w] = true;
edgeTo[w] = v;
}
}
}
}
public static void ClassInit(TestContext context)
{
basicGraph = new Graph(9);
basicGraph.AddEdge(0, 1);
basicGraph.AddEdge(0, 2);
basicGraph.AddEdge(0, 5);
basicGraph.AddEdge(0, 6);
basicGraph.AddEdge(2, 7);
basicGraph.AddEdge(6, 4);
basicGraph.AddEdge(4, 3);
basicGraph.AddEdge(4, 5);
baseicDigraph = new Digraph(7);
baseicDigraph.AddEdge(5, 0);
baseicDigraph.AddEdge(2, 4);
baseicDigraph.AddEdge(3, 2);
baseicDigraph.AddEdge(1, 2);
baseicDigraph.AddEdge(0, 1);
baseicDigraph.AddEdge(4, 3);
baseicDigraph.AddEdge(3, 5);
baseicDigraph.AddEdge(0, 2);
baseicDigraph.AddEdge(6, 5);
}
public Digraph Reverse()
{
var rev = new Digraph(this._V);
for (int v = 0; v < _V; v++)
{
foreach (int w in adj[v])
{
rev.AddEdge(w, v);
}
}
return rev;
}
public void Digraph_API_Test()
{
Digraph G = new Digraph(3);
G.AddEdge(0, 1);
G.AddEdge(0, 2);
List<int> e = new List<int>(G.Adj(0));
Assert.AreEqual(1, e[0]);
}
public void DepthFirstOrder_Test()
{
var G = new Digraph(4);
G.AddEdge(3, 2);
G.AddEdge(3, 1);
G.AddEdge(1, 0);
G.AddEdge(2, 0);
var DFO = new DepthFirstOrder(G);
var actual = new List<int>( DFO.GetReversePost());
Assert.AreEqual(3, actual[0]);
Assert.AreEqual(0, actual[3]);
}
