//We parametrize our insertion with the directed Boolean flag
// This is to identify whether we need to insert two copies of each edge or only one.
// Because Edges by themselves are always directional in Adjacency List
// So if (x,y) is an edge, in Undirected we need to add (y,x) too
private void InsertEdge(int x, int y, bool directed)
{
// create a node | We represent | Directed Edge (x, y) by an EdgeNode y in x's Adjacency List
EdgeNode edgeNode = new EdgeNode
{
// point the new Node to Edges[x]'s linked list
Next = Edges[x],
YValue = y,
Weight = null,
XThatComesFromEdgeIndexHereForDebugging = x
};
// Put the new node at the HEAD of the Adjacency Linked list
Edges[x] = edgeNode;
// Increase the degree
Degree[x] = Degree[x] + 1;
NEdges++;
if (!directed)
{
// The same edge has to appear in Y's Adjacency List | Thus graph is Undirected
InsertEdge(y, x, true);
}
}
public void PrintGraph()
{
for (int i = 0; i < NVertices; i++)
{
Console.WriteLine($"Vertex:{i}");;
EdgeNode edge = this.Edges[i];
while (edge != null)
{
Console.WriteLine($"{edge.YValue}");
edge = edge.Next;
}
}
}
public void PrintGraphBetter()
{
Console.WriteLine("-- START --");
for (int i = 0; i < NVertices; i++)
{
StringBuilder builder = new StringBuilder();
builder.Append($"Vertex:{i} ->");
EdgeNode edge = this.Edges[i];
while (edge != null)
{
builder.Append($"{edge.YValue}");
if (edge.Next != null)
{
builder.Append(" ->");
}
edge = edge.Next;
}
Console.WriteLine(builder.ToString());
}
Console.WriteLine("-- END --");
}
public Graph(int MAXV)
{
Edges = new EdgeNode[MAXV];
Degree = new int[MAXV];
MaxV = MAXV;
}