public List<Aresta> preparaArestas() {
List<Aresta> ar = new ArrayList<Aresta>();
for (int i = 0; i < Edges.size(); i++) {
Aresta current = Edges.get(i);
if (!(current.getFrom() == 0 || current.getTo() == 0)) {
ar.add(new Aresta(current.getFrom(), current.getTo(), current.getDistance()));
}
}
return ar;
}
/**
* Finds the minimum spanning tree of the given grapg with n vertices (the vertices are numbered
* 0, 1, ..., n-1)
*
* @param edges edges of the undirected graph
* @param nodeCount number of vertices (n)
* @return minimum spanning tree
*/
public List<Aresta> kruskalAlgorithm(List<Aresta> edges, int nodeCount) {
DisjointSet ds = new DisjointSet(nodeCount);
List<Aresta> spanningTree = new ArrayList<Aresta>();
Collections.sort(edges); // já vem ordenado
int i = 0;
while (i != edges.size() && spanningTree.size() != nodeCount - 1) {
Aresta e = edges.get(i);
if (ds.find(e.getFrom()) != ds.find(e.getTo())) {
spanningTree.add(e);
ds.union(e.getFrom(), e.getTo());
}
i++;
}
return spanningTree;
}
public List<Aresta> recolocaArestas(List<Aresta> ar, double[] u) {
int tot = 0;
for (int i = 0; i < Edges.size(); i++) {
if (tot == 2) {
break;
}
if (Edges.get(i).getFrom() == 0 || Edges.get(i).getTo() == 0) {
Aresta current = Edges.get(i);
ar.add(
new Aresta(
current.getFrom(),
current.getTo(),
current.getDistance())); // retorna as duas menores arestas do vertice inicial
ar.get(0)
.setDistance(ar.get(0).getDistance() + u[ar.get(0).getFrom()] + u[ar.get(0).getTo()]);
tot++;
}
}
return ar;
}
