public static List <Node> KahnAlgorithm(Graph graph)
{
var topSort = new List <Node>();
var nodes = graph.Nodes.ToList();
while (nodes.Count != 0)
{
var nodeToDelete = nodes
.Where(node => !node.IncidentEdges.Any(edge => edge.To == node))
.FirstOrDefault();
if (nodeToDelete == null)
{
return(null);
}
nodes.Remove(nodeToDelete);
topSort.Add(nodeToDelete);
foreach (var edge in nodeToDelete.IncidentEdges.ToList())
{
graph.Delete(edge);
}
}
return(topSort);
}
