public static int KruskalAlgorithm(UndirectedGenericGraph <int> graph)
{
var tree = new List <Vertex <int> >();
var edges = graph.Vertices.SelectMany(s => s.WeightedEdges).Distinct().OrderBy(w => w.Weight).ToList();
tree.Add(edges[0].StartV);
tree.Add(edges[0].EndV);
var cost = edges[0].Weight;
foreach (var weightedEdge in edges.Skip(1))
{
bool isfound = false;
if (!tree.Contains(weightedEdge.StartV))
{
tree.Add(weightedEdge.StartV);
isfound = true;
}
if (!tree.Contains(weightedEdge.EndV))
{
tree.Add(weightedEdge.EndV);
isfound = true;
}
if (isfound)
{
cost += weightedEdge.Weight;
}
}
return(cost);
}
public static void MinSpanTreeTest()
{
var graph = new UndirectedGenericGraph <int>();
var one = new Vertex <int>(1);
var two = new Vertex <int>(2);
var three = new Vertex <int>(3);
var four = new Vertex <int>(4);
var five = new Vertex <int>(5);
graph.AddPair(one, two, 5);
graph.AddPair(one, three, 3);
graph.AddPair(four, one, 6);
graph.AddPair(two, four, 7);
graph.AddPair(three, two, 4);
graph.AddPair(three, four, 5);
//graph.AddPair(one, two, 20);
//graph.AddPair(one, three, 50);
//graph.AddPair(one, four, 70);
//graph.AddPair(one, five, 90);
//graph.AddPair(two, three, 30);
//graph.AddPair(three, four, 40);
//graph.AddPair(four, five, 60);
var cost = KruskalAlgorithm(graph);
var cost2 = PrimeAlgorithm(graph);
var cost3 = DijkstraAlgorithmMinSpanTree(graph);//To be tested
}
public static void DijkstraAlgorithmTest()
{
var graph = new UndirectedGenericGraph <int>();
var one = new Vertex <int>(1);
var two = new Vertex <int>(2);
var three = new Vertex <int>(3);
var four = new Vertex <int>(4);
var five = new Vertex <int>(5);
var six = new Vertex <int>(6);
// graph.AddPair(one, two, 6);
// graph.AddPair(two, three, 6);
// graph.AddPair(three, four, 6);
// graph.AddPair(one, five, 6);
// graph.AddToList(six);
//graph.AddPair(one, two, 5);
//graph.AddPair(two, three, 6);
//graph.AddPair(three, four, 2);
//graph.AddPair(one, three, 15);
//graph.AddToList(five);
graph.AddPair(one, two, 24);
graph.AddPair(three, one, 3);
graph.AddPair(one, four, 20);
graph.AddPair(four, three, 12);
var start = one;
var distances = DijkstraAlgorithm(graph, start);
}
public static void BfsShortestReachInaGraph(Vertex <int> start)
{
var graph = new UndirectedGenericGraph <int>();
var one = new Vertex <int>(1);
var two = new Vertex <int>(2);
var three = new Vertex <int>(3);
var four = new Vertex <int>(4);
var five = new Vertex <int>(5);
var six = new Vertex <int>(6);
graph.AddPair(one, two, 6);
graph.AddPair(two, three, 6);
graph.AddPair(three, four, 6);
graph.AddPair(one, five, 6);
graph.AddToList(six);
var dict = graph.BreadthFirstSearchWeighted(graph.Vertices.FirstOrDefault(v => v.Value == start.Value));
var res3 = graph.Result;
//for (int i = 0; i < 6; i++)
//{
// graph.BreadthFirstSearch(graph.Vertices[i]);
// var res3 = graph.Result;
//}
}
public static List <int> DijkstraAlgorithm(UndirectedGenericGraph <int> graph, Vertex <int> start)
{
var vertices = graph.Vertices;
var n = vertices.Count;
var currDist = new Dictionary <Vertex <int>, int>(n);
foreach (var v in vertices)
{
currDist.Add(v, Int32.MaxValue);
}
currDist[start] = 0;
var toBeChecked = new List <Vertex <int> >(vertices);
while (toBeChecked.Count > 0)
{
var v = GetMinCurrDist(currDist, toBeChecked);
toBeChecked.Remove(v);
foreach (var u in vertices[v.Value - 1].Neighbors)
{
if (toBeChecked.Contains(u))
{
var edgevu = v.WeightedEdges.FirstOrDefault(w => (w.StartV == v && w.EndV == u) || (w.StartV == u && w.EndV == v));
if (edgevu != null)
{
var weightuv = edgevu.Weight;
if (currDist[u] > currDist[v] + weightuv)
{
currDist[u] = currDist[v] + weightuv;
}
}
}
}
}
//var count = toBeChecked.Count;
var currDict = currDist.OrderBy(s => s.Key.Value).ToList();
return(currDict.Select(s => s.Value).ToList());
//return null;// currDict.Values.ToList().Skip(1).ToList();
}
public static int DijkstraAlgorithmMinSpanTree(UndirectedGenericGraph <int> graph)
{
var tree = new List <Vertex <int> >();
var weightTree = new List <WeightedEdge <int> >();
var edges = graph.Vertices.SelectMany(s => s.WeightedEdges).Distinct().ToList();//.OrderBy(w => w.Weight).ToList();
weightTree.Add(edges[0]);
weightTree.Add(edges[1]);
foreach (var weightedEdge in edges.Skip(2))
{
weightTree.Add(weightedEdge);
var wt = ThereIsCycleInTheTree(weightTree);
if (wt != null)
{
weightTree.Remove(wt);
}
}
return(weightTree.Sum(s => s.Weight));
}
public static void CheckVertices()
{
var la = new Vertex <string>("Los Angeles");
var sf = new Vertex <string>("San Francisco");
var lv = new Vertex <string>("Las Vegas");
var se = new Vertex <string>("Seattle");
var au = new Vertex <string>("Austin");
var po = new Vertex <string>("Portland");
var aa = new Vertex <string>("Addis Ababa");
var ad = new Vertex <string>("Adama");
var testGraph = new UndirectedGenericGraph <string>();
// la <=> sf, lv, po
testGraph.AddPair(la, sf);
testGraph.AddPair(la, lv);
testGraph.AddPair(la, po);
// sf <=> se, po
testGraph.AddPair(sf, se);
testGraph.AddPair(sf, po);
// lv <=> au
testGraph.AddPair(lv, au);
// se <=> po
testGraph.AddPair(se, po);
// aa <=> ad
testGraph.AddToList(aa);
testGraph.AddToList(ad);
// Check to see that all neighbors are properly set up
foreach (var vertex in testGraph.Vertices)
{
Console.WriteLine(vertex.ToString());
//System.Diagnostics.Debug.WriteLine(vertex.ToString());
}
var resu = "";
for (int i = 0; i < 8; i++)
{
//if (!testGraph.Vertices[i].IsVisited)
//{
// testGraph.DepthFirstSearch(testGraph.Vertices[i]); //.FirstOrDefault(s=>s.Value=="Las Vegas"));
// var count = testGraph.Count;
// resu = testGraph.Result;
// testGraph.Result = "";
// testGraph.Count = 0;
//}
if (!testGraph.Vertices[i].IsVisited)
{
testGraph.DepthFirstSearchStack(testGraph.Vertices[i]);
var res3 = testGraph.Result;
}
}
testGraph.UnvisitAll();
var resu2 = "";
for (int i = 0; i < 8; i++)
{
if (!testGraph.Vertices[i].IsVisited)
{
testGraph.BreadthFirstSearch(testGraph.Vertices[i]); //.FirstOrDefault(s=>s.Value=="Las Vegas"));
//var count = testGraph.Count;
resu2 = testGraph.Result;
testGraph.Result = "";
//testGraph.Count = 0;
}
}
}