public List <List <int> > GetStroglyConnectedComponentsUsingDFS()
{
List <List <int> > stroglyConnectedComponentsList = new List <List <int> >();
List <int> dfsOrder = this.DFSTraversal();
dfsOrder.Reverse();
List <int> reverseDfsOrder = dfsOrder;
//run dfs on transpose graph
GraphAdj transposeGraph = this.GetTransposeGraph();
bool[] visited = new bool[this.V];
foreach (var vertex in reverseDfsOrder)
{
if (visited[vertex] == false)
{
List <int> stronglyConnectedComponentDfsOrderList = new List <int>();
transposeGraph.DFSTraversalInternalUtil(vertex, visited, stronglyConnectedComponentDfsOrderList);
stroglyConnectedComponentsList.Add(stronglyConnectedComponentDfsOrderList);
}
}
return(stroglyConnectedComponentsList);
}
private GraphAdj DeepCopy(GraphAdj source)
{
var DeserializeSettings = new JsonSerializerSettings {
ObjectCreationHandling = ObjectCreationHandling.Replace
};
return(JsonConvert.DeserializeObject <GraphAdj>(JsonConvert.SerializeObject(source), DeserializeSettings));
}
public GraphAdj GetTransposeGraph()
{
GraphAdj transposeGraph = new GraphAdj(this.V);
transposeGraph.adj = new List <AdjNode> [this.V];
for (int i = 0; i < this.V; i++)
{
transposeGraph.adj[i] = new List <AdjNode>(); //allocate actual memory
}
transposeGraph.Edges = new List <Edge>();
foreach (var edge in this.Edges)
{
transposeGraph.AddEdge(new Edge(edge.To, edge.From, edge.IsDirected, edge.Weight)); // reverse to and from
}
return(transposeGraph);
}
public void Run()
{
GraphAdj graph = new GraphAdj(6);
graph.AddDirectedEdge(0, 1);
graph.AddDirectedEdge(0, 2);
graph.AddDirectedEdge(1, 2);
graph.AddDirectedEdge(2, 0);
graph.AddDirectedEdge(2, 3);
graph.AddDirectedEdge(3, 3);
graph.AddDirectedEdge(4, 5);
List <int> dfsList = graph.DFSTraversal(2);
for (int i = 0; i < dfsList.Count; i++)
{
Console.WriteLine(dfsList[i] + ", ");
}
Console.WriteLine("---------DFS Reachable----------");
int from = 1;
int to = 3;
bool isReachable = graph.IsReachableUsingDFSLogic(from, to);
if (isReachable == true)
{
Console.WriteLine("{0} is reachable from {1}", to, from);
}
Console.WriteLine("---------BFS----------");
List <int> bfsList = graph.BFSTraversal(2);
for (int i = 0; i < bfsList.Count; i++)
{
Console.WriteLine(bfsList[i] + ", ");
}
Console.WriteLine("-------------------");
Console.WriteLine("Connected component count: {0}", graph.GetConnectedComponentCountUsingDFSLogic());
Console.WriteLine("----------Cycle using dfs---------");
bool isCyclic = graph.IsCyclicUsingDFSTraversalLogic();
if (isCyclic == true)
{
Console.WriteLine("Graph is cyclic...");
}
Console.WriteLine("--------Cycle using union find-----------");
GraphAdj undirectedGraph = new GraphAdj(4);
undirectedGraph.AddUnDirectedEdge(0, 1);
undirectedGraph.AddUnDirectedEdge(1, 2);
undirectedGraph.AddUnDirectedEdge(2, 0);
//WE CAN NOT FIND CYCLES IN DIRECTED GRAPH USING UNION FIND
bool isCyclicUndirected = undirectedGraph.IsCyclicUsingUnionFind();
if (isCyclicUndirected == true)
{
Console.WriteLine("Undirected Graph is cyclic using union find...");
}
Console.WriteLine("-------Floyd------------");
GraphAdj directedGraph = new GraphAdj(4);
directedGraph.AddDirectedEdge(0, 1, 5);
directedGraph.AddDirectedEdge(1, 3, 3);
directedGraph.AddDirectedEdge(3, 2, 1);
directedGraph.AddDirectedEdge(0, 3, 10);
int[,] solution = directedGraph.FloydWarshallAllPairShortestPaths();
for (int i = 0; i < solution.GetLength(0); i++)
{
for (int j = 0; j < solution.GetLength(1); j++)
{
Console.Write(solution[i, j] + " , ");
}
Console.WriteLine("");
}
Console.WriteLine("-------TOPO------------");
List <int> topologicalOrderForDag2 = directedGraph.TopologicalSortUsingIndegreeAndQueue();
foreach (var item in topologicalOrderForDag2)
{
Console.Write("{0}, ", item);
}
Console.WriteLine();
Console.WriteLine("-------FW------------");
bool[,] rechability = directedGraph.TransitiveClosureUsingFloydWarshallAllPairReachabilityMatrix();
for (int i = 0; i < rechability.GetLength(0); i++)
{
for (int j = 0; j < rechability.GetLength(1); j++)
{
Console.Write(rechability[i, j] + " , ");
}
Console.WriteLine("");
}
Console.WriteLine("-------DFS------------");
bool[,] rechabilityDFS = directedGraph.TransitiveClosureReachableUsingDFSForAllPair();
for (int i = 0; i < rechabilityDFS.GetLength(0); i++)
{
for (int j = 0; j < rechabilityDFS.GetLength(1); j++)
{
Console.Write(rechabilityDFS[i, j] + " , ");
}
Console.WriteLine("");
}
Console.WriteLine("-------------------");
GraphAdj undirectedGraph2 = new GraphAdj(4);
undirectedGraph2.AddUnDirectedEdge(0, 1, 10);
undirectedGraph2.AddUnDirectedEdge(0, 2, 6);
undirectedGraph2.AddUnDirectedEdge(0, 3, 5);
undirectedGraph2.AddUnDirectedEdge(1, 3, 15);
undirectedGraph2.AddUnDirectedEdge(2, 3, 4);
List <Edge> resultTree = undirectedGraph2.KruskalMST();
foreach (var edge in resultTree)
{
Console.WriteLine("From:{0}, To:{1}, Weight:{2}", edge.From, edge.To, edge.Weight);
}
Console.WriteLine("-------------------");
GraphAdj undirectedGraph3 = new GraphAdj(5);
undirectedGraph3.AddUnDirectedEdge(0, 1, 2);
undirectedGraph3.AddUnDirectedEdge(0, 3, 6);
undirectedGraph3.AddUnDirectedEdge(1, 2, 3);
undirectedGraph3.AddUnDirectedEdge(1, 3, 8);
undirectedGraph3.AddUnDirectedEdge(1, 4, 5);
undirectedGraph3.AddUnDirectedEdge(2, 4, 7);
undirectedGraph3.AddUnDirectedEdge(3, 4, 9);
List <Edge> resultTree3 = undirectedGraph3.PrimsMST();
foreach (var edge in resultTree3)
{
Console.WriteLine("From:{0}, To:{1}, Weight:{2}", edge.From, edge.To, edge.Weight);
}
Console.WriteLine("---------Dijkstra----------");
GraphAdj undirectedGraph4 = new GraphAdj(9);
undirectedGraph4.AddUnDirectedEdge(0, 1, 4);
undirectedGraph4.AddUnDirectedEdge(0, 7, 8);
undirectedGraph4.AddUnDirectedEdge(1, 2, 8);
undirectedGraph4.AddUnDirectedEdge(1, 7, 11);
undirectedGraph4.AddUnDirectedEdge(2, 3, 7);
undirectedGraph4.AddUnDirectedEdge(2, 8, 2);
undirectedGraph4.AddUnDirectedEdge(2, 5, 4);
undirectedGraph4.AddUnDirectedEdge(3, 4, 9);
undirectedGraph4.AddUnDirectedEdge(3, 5, 14);
undirectedGraph4.AddUnDirectedEdge(4, 5, 10);
undirectedGraph4.AddUnDirectedEdge(5, 6, 2);
undirectedGraph4.AddUnDirectedEdge(6, 7, 1);
undirectedGraph4.AddUnDirectedEdge(6, 8, 6);
undirectedGraph4.AddUnDirectedEdge(7, 8, 7);
Dictionary <int, int> vertexToShortestDistance = undirectedGraph4.DijkstraShortestPathFromSource(0);
Console.WriteLine("Source --> distance");
foreach (var item in vertexToShortestDistance)
{
Console.WriteLine("{0} --> {1}", item.Key, item.Value);
}
Console.WriteLine("---------Articulation Point----------");
GraphAdj undirectedGraph5 = new GraphAdj(5);
undirectedGraph5.AddUnDirectedEdge(1, 0);
undirectedGraph5.AddUnDirectedEdge(0, 2);
undirectedGraph5.AddUnDirectedEdge(2, 1);
undirectedGraph5.AddUnDirectedEdge(0, 3);
undirectedGraph5.AddUnDirectedEdge(3, 4);
List <int> articulationPoints = undirectedGraph5.ArticulationPointsOrCutVerticesUsingDFSLogic();
foreach (var item in articulationPoints)
{
Console.Write("{0}, ", item);
}
Console.WriteLine("");
Console.WriteLine("---------Articulation Point----------");
GraphAdj undirectedGraph6 = new GraphAdj(7);
undirectedGraph6.AddUnDirectedEdge(0, 1);
undirectedGraph6.AddUnDirectedEdge(1, 2);
undirectedGraph6.AddUnDirectedEdge(2, 0);
undirectedGraph6.AddUnDirectedEdge(1, 3);
undirectedGraph6.AddUnDirectedEdge(1, 4);
undirectedGraph6.AddUnDirectedEdge(1, 6);
undirectedGraph6.AddUnDirectedEdge(3, 5);
undirectedGraph6.AddUnDirectedEdge(4, 5);
List <int> articulationPoints2 = undirectedGraph6.ArticulationPointsOrCutVerticesUsingDFSLogic();
foreach (var item in articulationPoints2)
{
Console.Write("{0}, ", item);
}
Console.WriteLine("");
Console.WriteLine("--------BellmanFord-----------");
GraphAdj directedGraph2 = new GraphAdj(5);
directedGraph2.AddDirectedEdge(0, 1, -1);
directedGraph2.AddDirectedEdge(0, 2, 4);
directedGraph2.AddDirectedEdge(1, 2, 3);
directedGraph2.AddDirectedEdge(1, 3, 2);
directedGraph2.AddDirectedEdge(1, 4, 2);
directedGraph2.AddDirectedEdge(3, 2, 5);
directedGraph2.AddDirectedEdge(3, 1, 1);
directedGraph2.AddDirectedEdge(4, 3, -3);
bool negativeCycleFlag = false;
Dictionary <int, int> vertexToShortestDistanceBellmanFord = directedGraph2.BellmanFordShortestPathWithNegativeCycles(0, ref negativeCycleFlag);
if (negativeCycleFlag == false)
{
foreach (var item in vertexToShortestDistanceBellmanFord)
{
Console.WriteLine("{0} --> {1}", item.Key, item.Value);
}
}
else
{
Console.WriteLine("Negative weight cycle present...");
}
Console.WriteLine("---------TOPOLOGICAL SORT----------");
bool noCycleAndTopoLogicalPossible = false;
List <int> topologicalOrder = directedGraph2.TopologicalSortingUsingDFSWithStack(ref noCycleAndTopoLogicalPossible);
if (noCycleAndTopoLogicalPossible == true)
{
foreach (var item in topologicalOrder)
{
Console.Write("{0}, ", item);
}
Console.WriteLine();
}
else
{
Console.WriteLine("Cycle found!!! No topological ordering..");
}
Console.WriteLine("--------DAG-----------");
GraphAdj directedAcyclicGraph = new GraphAdj(6);
directedAcyclicGraph.AddDirectedEdge(0, 1, 5);
directedAcyclicGraph.AddDirectedEdge(0, 2, 3);
directedAcyclicGraph.AddDirectedEdge(1, 3, 6);
directedAcyclicGraph.AddDirectedEdge(1, 2, 2);
directedAcyclicGraph.AddDirectedEdge(2, 4, 4);
directedAcyclicGraph.AddDirectedEdge(2, 5, 2);
directedAcyclicGraph.AddDirectedEdge(2, 3, 7);
directedAcyclicGraph.AddDirectedEdge(3, 4, -1);
directedAcyclicGraph.AddDirectedEdge(4, 5, -2);
List <int> topologicalOrderForDag = directedAcyclicGraph.TopologicalSortUsingIndegreeAndQueue();
foreach (var item in topologicalOrderForDag)
{
Console.Write("{0}, ", item);
}
Console.WriteLine();
Console.WriteLine("---------Shortest Distance - DAG--------");
int source = 1;
Dictionary <int, int> vertexToShortestDistanceTopo = directedAcyclicGraph.DirectedAcyclicGraphShortestPathFromSourceUsingTopoLogicalSortOrder(source);
Console.WriteLine("Source --> distance");
foreach (var item in vertexToShortestDistanceTopo)
{
Console.WriteLine("{0}->{1} ", item.Key, item.Value);
}
Console.WriteLine("-------SCC----------");
GraphAdj directedGraph3 = new GraphAdj(5);
directedGraph3.AddDirectedEdge(1, 0);
directedGraph3.AddDirectedEdge(0, 2);
directedGraph3.AddDirectedEdge(2, 1);
directedGraph3.AddDirectedEdge(0, 3);
directedGraph3.AddDirectedEdge(3, 4);
List <List <int> > sccList = directedGraph3.GetStroglyConnectedComponentsUsingDFS();
foreach (var scc in sccList)
{
foreach (var vertex in scc)
{
Console.Write("{0}, ", vertex);
}
Console.WriteLine("");
}
Console.WriteLine("-----------------");
GraphAdj directedGraph4 = new GraphAdj(6);
directedGraph4.AddDirectedEdge(0, 1, 16);
directedGraph4.AddDirectedEdge(0, 2, 13);
directedGraph4.AddDirectedEdge(1, 2, 10);
directedGraph4.AddDirectedEdge(1, 3, 12);
directedGraph4.AddDirectedEdge(2, 1, 4);
directedGraph4.AddDirectedEdge(2, 4, 14);
directedGraph4.AddDirectedEdge(3, 2, 9);
directedGraph4.AddDirectedEdge(3, 5, 20);
directedGraph4.AddDirectedEdge(4, 3, 7);
directedGraph4.AddDirectedEdge(4, 5, 4);
int maxFlow = directedGraph4.FordFulkarsonMaximumFlow(0, 5);
Console.WriteLine("Max Flow: {0}", maxFlow);
Console.WriteLine("-----------------");
int numberToRepresentMultipleInZeroOne = 55;
GraphAdj directedGraphForNumber = new GraphAdj(numberToRepresentMultipleInZeroOne);
String resultString = directedGraphForNumber.GetMultipleInZeroOneOnlyFor(numberToRepresentMultipleInZeroOne);
Console.WriteLine("Multiple of {0} -> {1}", numberToRepresentMultipleInZeroOne, resultString);
Console.WriteLine("-----------------");
Console.ReadKey();
}