public void RemoveNeighbor(DirectedGraphNode <T> neighborToRemove)
{
if (m_Neighbors.Contains(neighborToRemove))
{
m_Neighbors.Remove(neighborToRemove);
}
}
/// <summary>
/// Adds an edge to the directed graph. The direction is from the head vertex to the tail vertex.
/// </summary>
/// <param name="headVertex"></param>
/// <param name="tailVertex"></param>
public void AddEdge(T headVertex, T tailVertex)
{
if (headVertex == null)
{
throw new ArgumentNullException(nameof(headVertex));
}
if (tailVertex == null)
{
throw new ArgumentNullException(nameof(tailVertex));
}
bool headIndex = Nodes.ContainsKey(headVertex);
bool tailIndex = Nodes.ContainsKey(tailVertex);
if (!headIndex)
{
DirectedGraphNode <T> nodeOne = new DirectedGraphNode <T>(headVertex);
Nodes.Add(headVertex, nodeOne);
}
if (!tailIndex)
{
DirectedGraphNode <T> nodeTwo = new DirectedGraphNode <T>(tailVertex);
Nodes.Add(tailVertex, nodeTwo);
}
Nodes[headVertex].AddNeighbor(Nodes[tailVertex]);
}
public void AddNeighbor(DirectedGraphNode <T> neighborToAdd)
{
if (!m_Neighbors.Contains(neighborToAdd))
{
m_Neighbors.Add(neighborToAdd);
}
}
public DirectedGraph(T initialNodeData)
{
Nodes = new Dictionary <T, DirectedGraphNode <T> >();
DirectedGraphNode <T> initialNode = new DirectedGraphNode <T>(initialNodeData);
Nodes.Add(initialNodeData, initialNode);
NumberOfComponents = 0;
}
public void AddVertex(T vertex)
{
bool v2Index = Nodes.ContainsKey(vertex);
if (!v2Index)
{
DirectedGraphNode <T> newNode = new DirectedGraphNode <T>(vertex);
Nodes.Add(vertex, newNode);
}
}
/// <summary>
/// Generic BFS function. Can be used to solve any problem that requires BFS, just plug in the inspectionFunc.
/// </summary>
/// <param name="inspectFunc">Must return true if the search is completed and no more nodes need to be checked</param>
/// <param name="startId">Starting node, by default it is 0.</param>
public void Bfs(Func <DirectedGraphNode <T>, bool> inspectFunc, bool countComponents)
{
List <DirectedGraphNode <T> > nodes = Nodes.Values.ToList();
if (nodes.Count == 0)
{
return;
}
bool[] visited = new bool[nodes.Count];
visited.Initialize();
Queue <DirectedGraphNode <T> > nodeQueue = new Queue <DirectedGraphNode <T> >();
foreach (var undirectedGraphNode in nodes)
{
int currentNodeId = nodes.IndexOf(undirectedGraphNode);
if (!visited[currentNodeId])
{
if (countComponents)
{
NumberOfComponents++;
}
nodeQueue.Enqueue(undirectedGraphNode);
visited[currentNodeId] = true;
while (nodeQueue.Count != 0)
{
DirectedGraphNode <T> currentNode = nodeQueue.Dequeue();
if (inspectFunc != null && inspectFunc(currentNode))
{
return;
}
foreach (DirectedGraphNode <T> neighbor in currentNode.GetNeighbors())
{
if (!visited[nodes.IndexOf(neighbor)])
{
visited[nodes.IndexOf(neighbor)] = true;
nodeQueue.Enqueue(neighbor);
}
}
}
}
}
}
private void InternalDfs(List <DirectedGraphNode <T> > nodes, bool[] visited, DirectedGraphNode <T> node, Func <DirectedGraphNode <T>, bool> inspectFunc)
{
int nodeId = nodes.IndexOf(node);
visited[nodeId] = true;
int childLoopItteration = 0;
foreach (DirectedGraphNode <T> neighbor in node.GetNeighbors())
{
if (inspectFunc(neighbor))
{
return;
}
if (!visited[nodes.IndexOf(neighbor)])
{
InternalDfs(nodes, visited, neighbor, inspectFunc);
}
childLoopItteration++;
}
}
public DirectedGraphNode(DirectedGraphNode <T> initialNeighbor, T data) : this(data)
{
m_Neighbors.Add(initialNeighbor);
}