public DataDirectedGraph CreateReverse()
{
int n = Graph.Vertexes.Length;
DataDirectedGraph r = new DataDirectedGraph();
r.CountVertexes = n;
r.Graph = new GraphAdj();
r.Graph.Vertexes = new List<int>[n];
for(int i = 0; i < n; i++)
{
r.Graph.Vertexes[i] = new List<int>();
}
for (int v = 0; v < n; v++)
{
if (Graph.Vertexes[v] == null)
{
continue;
}
foreach (int w in Graph.Vertexes[v])
{
r.Graph.Vertexes[w].Add(v);
r.CountEdges++;
}
}
return r;
}
static void Main(string[] args)
{
DataDirectedGraph data = new DataDirectedGraph("Strongly Connected Components.txt");
//data.Print();
//Console.WriteLine("\r\nFinish!");
//Console.ReadKey();
int r = StronglyConnectedComponents(data);
Console.WriteLine(r);
Console.WriteLine("\r\nFinish!");
Console.ReadKey();
}
static private void DfsOnReverse(DataDirectedGraph g, int v)
{
markedReverse[v] = true;
foreach (int w in g.Graph.Vertexes[v])
{
if (markedReverse[w])
{
continue;
}
DfsOnReverse(g, w);
}
postOrder.Enqueue(v);
}
static void Main(string[] args)
{
DataDirectedGraph graph = new DataDirectedGraph("Topological Sorting.txt");
//graph.Print();
//Console.WriteLine("Finish!");
//Console.ReadKey();
int[] r = TopologicalSorting(graph);
Utils.PrintArrayToFile(r);
Console.WriteLine();
Console.WriteLine("Finish!");
Console.ReadKey();
}
private static void DFS(DataDirectedGraph g, int v)
{
if (marked[v] != 0)
{
return;
}
marked[v] = 1;
if (null != g.Graph.Vertexes[v])
{
foreach (int i in g.Graph.Vertexes[v])
{
DFS(g, i);
}
}
reversePost.Push(v);
}
static int StronglyConnectedComponents(DataDirectedGraph g)
{
int n = g.Graph.Vertexes.Length;
DataDirectedGraph r = g.CreateReverse();
postOrder = new Queue<int>();
markedReverse = new bool[n];
for (int v = 0; v < n; v++)
{
if (markedReverse[v])
{
continue;
}
DfsOnReverse(r, v);
}
marked = new bool[n];
id = new int[n];
Stack<int> queueReversePost = new Stack<int>();
foreach (int v in postOrder)
{
queueReversePost.Push(v);
}
foreach (int v in queueReversePost)
{
if (marked[v])
{
continue;
}
Dfs(g, v);
count++;
}
return count;
}
private static int[] TopologicalSorting(DataDirectedGraph g)
{
int n = g.Graph.Vertexes.Length;
marked = new int[n];
reversePost = new Stack<int>();
for (int v = 0; v < n; v++)
{
DFS(g, v);
}
int[] r = new int[reversePost.Count];
int i = 0;
while (reversePost.Count != 0)
{
r[i] = reversePost.Pop() + 1;
i++;
}
return r;
}
static private void Dfs(DataDirectedGraph g, int v)
{
marked[v] = true;
id[v] = count;
if (g.Graph.Vertexes[v] == null)
{
return;
}
foreach (int w in g.Graph.Vertexes[v])
{
if (marked[w])
{
continue;
}
Dfs(g, w);
}
}