public static Graph Boruvka(Graph graph)
{
var result = new Graph();
result.Vertexes = graph.Vertexes;
var disjointForest = new DisjointSetUnionTree(result.Vertexes);
while (result.Edges.Count < result.Vertexes.Count - 1) {
var safe = new Dictionary<int, Edge<int>>();
foreach (var edge in graph.Edges) {
var fromRoot = disjointForest.Find(edge.From);
var toRoot = disjointForest.Find(edge.To);
if (fromRoot != toRoot) {
if (!safe.ContainsKey(fromRoot) || edge.Weight < safe[fromRoot].Weight) {
safe[fromRoot] = edge;
}
if (!safe.ContainsKey(toRoot) || edge.Weight < safe[toRoot].Weight) {
safe[toRoot] = edge;
}
}
}
result.Edges.AddRange(safe.Values.Distinct());
foreach (var edge in safe.Values) {
disjointForest.Union(edge.From, edge.To);
}
}
return result;
}
public static Graph Kruskal(Graph inputGraph)
{
var result = new Graph();
result.Vertexes = inputGraph.Vertexes;
var edges = inputGraph.Edges.ToList();
edges.Sort();
var enumerator = edges.GetEnumerator();
var disjointSetUnion = new DisjointSetUnionTree(inputGraph.Vertexes);
while (result.Edges.Count < result.Vertexes.Count - 1) {
enumerator.MoveNext();
var edge = enumerator.Current;
var fromRoot = disjointSetUnion.Find(edge.From);
var toRoot = disjointSetUnion.Find(edge.To);
if (fromRoot != toRoot) {
disjointSetUnion.Union(edge.From, edge.To);
result.Edges.Add(edge);
}
}
return result;
}
public static int Cluster(Graph graph, int clusterCount)
{
var result = new Graph {
Vertexes = graph.Vertexes
};
var edges = graph.Edges.ToList();
edges.Sort();
var enumerator = edges.GetEnumerator();
var disjointSetUnion = new DisjointSetUnionTree(graph.Vertexes);
while (disjointSetUnion.Count != clusterCount - 1) {
enumerator.MoveNext();
var edge = enumerator.Current;
var fromRoot = disjointSetUnion.Find(edge.From);
var toRoot = disjointSetUnion.Find(edge.To);
if (fromRoot != toRoot) {
disjointSetUnion.Union(fromRoot, toRoot);
result.Edges.Add(edge);
}
}
return enumerator.Current.Weight;
}
public static Graph GenerateTree(int vertexes)
{
var result = new Graph();
for (var i = 0; i < vertexes; i++)
{
result.Vertexes.Add(i);
}
var disjointSet = new DisjointSetUnionTree(result.Vertexes);
while (result.Edges.Count < result.Vertexes.Count - 1)
{
var from = random.Next(vertexes);
var to = random.Next(vertexes);
if (from == to || disjointSet.Find(from) == disjointSet.Find(to))
{
continue;
}
result.Edges.Add(new Edge <int>(from, to, 0));
disjointSet.Union(from, to);
}
return(result);
}
public static Graph Kruskal(Graph inputGraph)
{
var result = new Graph();
result.Vertexes = inputGraph.Vertexes;
var edges = inputGraph.Edges.ToList();
edges.Sort(new WeightComparer <int>());
var disjointSetUnion = new DisjointSetUnionTree(inputGraph.Vertexes);
foreach (var edge in edges)
{
var fromRoot = disjointSetUnion.Find(edge.From);
var toRoot = disjointSetUnion.Find(edge.To);
if (fromRoot != toRoot)
{
disjointSetUnion.Union(fromRoot, toRoot);
result.Edges.Add(edge);
}
}
return(result);
}
public static Graph Boruvka(Graph graph)
{
var result = new Graph();
result.Vertexes = graph.Vertexes;
var disjointForest = new DisjointSetUnionTree(result.Vertexes);
while (result.Edges.Count < result.Vertexes.Count - 1)
{
var safe = new Dictionary <int, Edge <int> >();
foreach (var edge in graph.Edges)
{
var fromRoot = disjointForest.Find(edge.From);
var toRoot = disjointForest.Find(edge.To);
if (fromRoot != toRoot)
{
if (!safe.ContainsKey(fromRoot) || edge.Weight < safe[fromRoot].Weight)
{
safe[fromRoot] = edge;
}
if (!safe.ContainsKey(toRoot) || edge.Weight < safe[toRoot].Weight)
{
safe[toRoot] = edge;
}
}
}
result.Edges.AddRange(safe.Values.Distinct());
foreach (var edge in safe.Values)
{
disjointForest.Union(edge.From, edge.To);
}
}
return(result);
}
public static Graph Kruskal(Graph inputGraph)
{
var result = new Graph();
result.Vertexes = inputGraph.Vertexes;
var edges = inputGraph.Edges.ToList();
edges.Sort(new WeightComparer<int>());
var disjointSetUnion = new DisjointSetUnionTree(inputGraph.Vertexes);
foreach (var edge in edges) {
var fromRoot = disjointSetUnion.Find(edge.From);
var toRoot = disjointSetUnion.Find(edge.To);
if (fromRoot != toRoot) {
disjointSetUnion.Union(fromRoot, toRoot);
result.Edges.Add(edge);
}
}
return result;
}
public static Graph GenerateTree(int vertexes)
{
var result = new Graph();
for (var i = 0; i < vertexes; i++) {
result.Vertexes.Add(i);
}
var disjointSet = new DisjointSetUnionTree(result.Vertexes);
while (result.Edges.Count < result.Vertexes.Count - 1) {
var from = random.Next(vertexes);
var to = random.Next(vertexes);
if (from == to || disjointSet.Find(from) == disjointSet.Find(to)) continue;
result.Edges.Add(new Edge<int>(from, to, 0));
disjointSet.Union(from, to);
}
return result;
}
public void DisjointSetUnionTreeTest()
{
var disjointSetUnionArray = new DisjointSetUnionTree(new[] {4, 3, 2, 1, 0});
TestAgainstComplexInput(disjointSetUnionArray);
}
public void DisjointSetUnionTreeTest()
{
var disjointSetUnionArray = new DisjointSetUnionTree(new[] { 4, 3, 2, 1, 0 });
TestAgainstComplexInput(disjointSetUnionArray);
}
