public WeightedGraph GetMinimumSpanningTree()
{
var tree = new WeightedGraph();
if (nodes == null)
{
return(tree);
}
var startNode = nodes.Values.First();
var edges = startNode.GetEdges();
if (edges == null)
{
return(tree);
}
tree.AddNode(startNode.Label);
while (tree.nodes.Count() < nodes.Count())
{
var minEdge = edges.OrderBy(e => e.Weight).First();
var nextNode = minEdge.To;
edges.Remove(minEdge);
if (tree.ContainsNode(nextNode.Label))
{
continue;
}
tree.AddNode(nextNode.Label);
tree.AddEdge(minEdge.From.Label, nextNode.Label, minEdge.Weight);
foreach (var edge in nextNode.GetEdges())
{
if (!tree.ContainsNode(edge.To.Label))
{
edges.Add(edge);
}
}
}
return(tree);
}
static void Main(string[] args)
{
var graph = new Graph();
graph.AddNode("David");
graph.AddNode("John");
graph.AddNode("Peter");
graph.AddEdge("David", "John");
graph.AddEdge("David", "Peter");
graph.AddEdge("John", "Peter");
graph.RemoveEdge("David", "Peter");
graph.RemoveEdge("A", "B");
graph.RemoveNode("John");
graph.Print();
var graph1 = new Graph();
graph1.AddNode("A");
graph1.AddNode("B");
graph1.AddNode("C");
graph1.AddNode("D");
graph1.AddEdge("A", "B");
graph1.AddEdge("B", "D");
graph1.AddEdge("D", "C");
graph1.AddEdge("A", "C");
graph1.TraverseDepthFirstRecursive("A");
graph1.TraverseDepthFirstIterative("A");
graph1.TraverseBreadthFirstIterative("A");
var graph2 = new Graph();
graph2.AddNode("X");
graph2.AddNode("A");
graph2.AddNode("B");
graph2.AddNode("P");
graph2.AddEdge("X", "A");
graph2.AddEdge("X", "B");
graph2.AddEdge("A", "P");
graph2.AddEdge("B", "P");
var nodes = graph2.TopologicalSort();
foreach (var node in nodes)
{
System.Console.WriteLine(node);
}
var graph3 = new Graph();
graph3.AddNode("A");
graph3.AddNode("B");
graph3.AddNode("C");
graph3.AddEdge("A", "B");
graph3.AddEdge("B", "C");
graph3.AddEdge("C", "A");
System.Console.WriteLine(graph3.HasCycle());
var weightedGraph = new WeightedGraph();
weightedGraph.AddNode("A");
weightedGraph.AddNode("B");
weightedGraph.AddNode("C");
weightedGraph.AddEdge("A", "B", 3);
weightedGraph.AddEdge("A", "C", 2);
weightedGraph.Print();
var weightedGraph1 = new WeightedGraph();
weightedGraph1.AddNode("A");
weightedGraph1.AddNode("B");
weightedGraph1.AddNode("C");
weightedGraph1.AddEdge("A", "B", 1);
weightedGraph1.AddEdge("B", "C", 2);
weightedGraph1.AddEdge("A", "C", 10);
var path = weightedGraph1.GetShortestPath("A", "C");
System.Console.WriteLine(path);
var weightedGraph2 = new WeightedGraph();
weightedGraph2.AddNode("A");
weightedGraph2.AddNode("B");
weightedGraph2.AddNode("C");
weightedGraph2.AddEdge("A", "B", 0);
weightedGraph2.AddEdge("B", "C", 0);
weightedGraph2.AddEdge("C", "A", 0);
System.Console.WriteLine(weightedGraph2.HasCycle());
var weightedGraph3 = new WeightedGraph();
weightedGraph3.AddNode("A");
weightedGraph3.AddNode("B");
weightedGraph3.AddNode("C");
weightedGraph3.AddNode("D");
weightedGraph3.AddEdge("A", "B", 3);
weightedGraph3.AddEdge("B", "D", 4);
weightedGraph3.AddEdge("C", "D", 5);
weightedGraph3.AddEdge("A", "C", 1);
weightedGraph3.AddEdge("B", "C", 2);
var tree = weightedGraph3.GetMinimumSpanningTree();
tree.Print();
}