// Note that this algorithm could leave disjoint graphs, especially if number of nodes is low
private void FullConnectThenSubtract(Graph graph, double interconnectedness)
{
List <long> edges = new List <long>();
for (int from = 0; from < graph.NodeCount - 1; from++)
{
for (int to = from + 1; to < graph.NodeCount; to++)
{
edges.Add(from * graph.NodeCount + to); // Encode 2 integers in one long
}
}
int fullConnectionCount = graph.NodeCount * (graph.NodeCount - 1) / 2;
int toCreate = (int)(fullConnectionCount * interconnectedness);
for (int ii = 0; ii < toCreate; ii++)
{
int index = _random.Next(edges.Count);
long item = edges[index];
int from = (int)(item / graph.NodeCount);
int to = (int)(item % graph.NodeCount);
graph.Connect(from, to);
edges.RemoveAt(index);
}
}
private void AddEdges(Graph graph, double interconnectedness)
{
// Randomly add nodes to make a tree
for (int ii = 0; ii < graph.NodeCount; ii++)
{
if (ii > 0)
{
int from = _random.Next(ii);
graph.Connect(from, ii);
}
}
int fullConnectionCount = graph.NodeCount * (graph.NodeCount - 1) / 2;
int addedAtCreation = graph.NodeCount - 1; // These many edges were added at creation
int toCreate = (int)((fullConnectionCount - addedAtCreation) * interconnectedness);
int created = 0;
while (created < toCreate)
{
int from = _random.Next(graph.NodeCount);
int to = _random.Next(graph.NodeCount);
if (!graph.AllowLoops && from == to)
{
continue;
}
if (graph.HasEdge(from, to))
{
continue;
}
graph.Connect(from, to);
created++;
}
}
