public void calculateTspCycle() {
AllShortestPaths shortestPaths = new AllShortestPaths(this.graph);
shortestPaths.compute();
Graph augmentedGraph = shortestPaths.toDistancesGraph();
MinimumSpanningTree minTree = new MinimumSpanningTree(augmentedGraph);
minTree.compute();
Graph tree = minTree.getMinimumTree();
int oddNodes = 0;
for (int node = 0; node < tree.getNumNodes(); node++) {
if (tree.getOutEdges(node).size() % 2 == 1) {
oddNodes++;
}
}
System.out.println("Nodes with odd degree: " + oddNodes);
// formar um subgrafo so com os nos ímpares
Graph oddGraph = null;
// emparelhar nos impares
// OBS: nao é esse algoritmo
// ver: http://en.wikipedia.org/wiki/Edmonds%27s_matching_algorithm
MaximumBipartiteMatching matchingAlgorithm = new MaximumBipartiteMatching(oddGraph);
matchingAlgorithm.compute();
List<Edge> newEdges = matchingAlgorithm.getMatching();
for (Edge edge : newEdges) {
tree.addUndirectedEdge(edge.getSource(), edge.getTarget(), edge.getLength());
}
// formar o caminho euleriano...
// Hierholzer's algorithm
Path cycle = null;
// criar os atalhos
// trocar as arestas por caminhos do grafo original
tspCycle = cycle.expandShortestPaths(shortestPaths);
}
public static void main(String[] args) throws IOException {
Graph graph = GraphFileUtil.readAdjacencyList("src\\tests\\graph\\grafo-11.txt");
MinimumSpanningTree minTree = new MinimumSpanningTree(graph);
minTree.compute();
/* Custo da árvore esperado no "grafo-11": 39
*/
System.out.println();
System.out.println("Cost: " + minTree.getMinimumTreeCost());
System.out.println();
System.out.print("The tree:");
System.out.println(minTree.getMinimumTree());
ChristofidesTspApproximation tspSolver = new ChristofidesTspApproximation(graph);
tspSolver.calculateTspCycle();
}
