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Code Issues 4 Releases Wiki Activity

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Holt59
2018-03-25 14:35:15 +02:00
parent 5b733e25c7
commit aab8743d3c
24 changed files with 893 additions and 388 deletions
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133
src/main/org/insa/algo/shortestpath/BellmanFordAlgorithm.java
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@@ -4,7 +4,6 @@ import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import org.insa.algo.AbstractInputData;
import org.insa.algo.AbstractSolution.Status;
import org.insa.graph.Arc;
import org.insa.graph.Graph;
@@ -13,90 +12,88 @@ import org.insa.graph.Path;
public class BellmanFordAlgorithm extends ShortestPathAlgorithm {
public BellmanFordAlgorithm(ShortestPathData data) {
super(data);
}
public BellmanFordAlgorithm(ShortestPathData data) {
super(data);
}
@Override
protected ShortestPathSolution doRun() {
@Override
protected ShortestPathSolution doRun() {
// Retrieve the graph.
ShortestPathData data = getInputData();
Graph graph = data.getGraph();
// Retrieve the graph.
ShortestPathData data = getInputData();
Graph graph = data.getGraph();
final int nbNodes = graph.size();
final int nbNodes = graph.size();
// Initialize array of distances.
double[] distances = new double[nbNodes];
Arrays.fill(distances, Double.POSITIVE_INFINITY);
distances[data.getOrigin().getId()] = 0;
// Initialize array of distances.
double[] distances = new double[nbNodes];
Arrays.fill(distances, Double.POSITIVE_INFINITY);
distances[data.getOrigin().getId()] = 0;
// Notify observers about the first event (origin processed).
notifyOriginProcessed(data.getOrigin());
// Notify observers about the first event (origin processed).
notifyOriginProcessed(data.getOrigin());
// Initialize array of predecessors.
Arc[] predecessorArcs = new Arc[nbNodes];
// Initialize array of predecessors.
Arc[] predecessorArcs = new Arc[nbNodes];
// Actual algorithm, we will assume the graph does not contain negative cycle...
boolean found = false;
for (int i = 0; !found && i < nbNodes; ++i) {
found = true;
for (Node node: graph) {
for (Arc arc: node) {
// Actual algorithm, we will assume the graph does not contain negative
// cycle...
boolean found = false;
for (int i = 0; !found && i < nbNodes; ++i) {
found = true;
for (Node node : graph) {
for (Arc arc : node) {
// Small test to check allowed roads...
if (!data.isAllowed(arc)) {
continue;
}
// Small test to check allowed roads...
if (!data.isAllowed(arc)) {
continue;
}
// Retrieve weight of the arc.
double w = data.getMode() == AbstractInputData.Mode.LENGTH ? arc.getLength()
: arc.getMinimumTravelTime();
// Retrieve weight of the arc.
double w = data.getCost(arc);
double oldDistance = distances[arc.getDestination().getId()];
double newDistance = distances[node.getId()] + w;
double oldDistance = distances[arc.getDestination().getId()];
double newDistance = distances[node.getId()] + w;
if (Double.isInfinite(oldDistance) && Double.isFinite(newDistance)) {
notifyNodeReached(arc.getDestination());
}
if (Double.isInfinite(oldDistance) && Double.isFinite(newDistance)) {
notifyNodeReached(arc.getDestination());
}
// Check if new distances would be better, if so update...
if (newDistance < oldDistance) {
found = false;
distances[arc.getDestination().getId()] = distances[node.getId()] + w;
predecessorArcs[arc.getDestination().getId()] = arc;
}
}
}
}
// Check if new distances would be better, if so update...
if (newDistance < oldDistance) {
found = false;
distances[arc.getDestination().getId()] = distances[node.getId()] + w;
predecessorArcs[arc.getDestination().getId()] = arc;
}
}
}
}
ShortestPathSolution solution = null;
ShortestPathSolution solution = null;
// Destination has no predecessor, the solution is infeasible...
if (predecessorArcs[data.getDestination().getId()] == null) {
solution = new ShortestPathSolution(data, Status.INFEASIBLE);
} else {
// Destination has no predecessor, the solution is infeasible...
if (predecessorArcs[data.getDestination().getId()] == null) {
solution = new ShortestPathSolution(data, Status.INFEASIBLE);
}
else {
// The destination has been found, notify the observers.
notifyDestinationReached(data.getDestination());
// The destination has been found, notify the observers.
notifyDestinationReached(data.getDestination());
// Create the path from the array of predecessors...
ArrayList<Arc> arcs = new ArrayList<>();
Arc arc = predecessorArcs[data.getDestination().getId()];
while (arc != null) {
arcs.add(arc);
arc = predecessorArcs[arc.getOrigin().getId()];
}
// Create the path from the array of predecessors...
ArrayList<Arc> arcs = new ArrayList<>();
Arc arc = predecessorArcs[data.getDestination().getId()];
while (arc != null) {
arcs.add(arc);
arc = predecessorArcs[arc.getOrigin().getId()];
}
// Reverse the path...
Collections.reverse(arcs);
// Reverse the path...
Collections.reverse(arcs);
// Create the final solution.
solution = new ShortestPathSolution(data, Status.OPTIMAL, new Path(graph, arcs));
}
// Create the final solution.
solution = new ShortestPathSolution(data, Status.OPTIMAL, new Path(graph, arcs));
}
return solution;
}
return solution;
}
}

28
src/main/org/insa/algo/shortestpath/ShortestPathData.java
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@@ -1,6 +1,7 @@
package org.insa.algo.shortestpath;
import org.insa.algo.AbstractInputData;
import org.insa.algo.ArcInspector;
import org.insa.graph.Graph;
import org.insa.graph.Node;
@@ -9,34 +10,17 @@ public class ShortestPathData extends AbstractInputData {
// Origin and destination nodes.
private final Node origin, destination;
/**
* Construct a new instance of ShortestPathData with the given parameters and
* for which all arcs are allowed.
*
* @param graph Graph in which the path should be looked for.
* @param origin Origin node of the path.
* @param destination Destination node of the path.
* @param mode Cost mode for the path.
*/
public ShortestPathData(Graph graph, Node origin, Node destination, Mode mode) {
super(graph, mode);
this.origin = origin;
this.destination = destination;
}
/**
* Construct a new instance of ShortestPathInputData with the given parameters.
*
* @param graph Graph in which the path should be looked for.
* @param origin Origin node of the path.
* @param destination Destination node of the path.
* @param mode Cost mode for the path.
* @param arcFilter Filter for arcs (used to allow only a specific set of arcs
* in the graph to be used).
* @param arcInspector Filter for arcs (used to allow only a specific set of
* arcs in the graph to be used).
*/
public ShortestPathData(Graph graph, Node origin, Node destination, Mode mode,
AbstractInputData.ArcFilter arcFilter) {
super(graph, mode, arcFilter);
public ShortestPathData(Graph graph, Node origin, Node destination, ArcInspector arcInspector) {
super(graph, arcInspector);
this.origin = origin;
this.destination = destination;
}
@@ -58,6 +42,6 @@ public class ShortestPathData extends AbstractInputData {
@Override
public String toString() {
return "Shortest-path from #" + origin.getId() + " to #" + destination.getId() + " ["
+ getMode().toString().toLowerCase() + "]";
+ this.arcInspector.toString().toLowerCase() + "]";
}
}

14
src/main/org/insa/algo/shortestpath/ShortestPathSolution.java
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@@ -1,7 +1,8 @@
package org.insa.algo.shortestpath;
import org.insa.algo.AbstractInputData;
import org.insa.algo.AbstractInputData.Mode;
import org.insa.algo.AbstractSolution;
import org.insa.graph.Arc;
import org.insa.graph.Path;
public class ShortestPathSolution extends AbstractSolution {
@@ -59,14 +60,17 @@ public class ShortestPathSolution extends AbstractSolution {
getInputData().getOrigin().getId(), getInputData().getDestination().getId());
}
else {
double cost = 0;
for (Arc arc: getPath().getArcs()) {
cost += getInputData().getCost(arc);
}
info = String.format("Found a path from node #%d to node #%d",
getInputData().getOrigin().getId(), getInputData().getDestination().getId());
if (getInputData().getMode() == AbstractInputData.Mode.LENGTH) {
info = String.format("%s, %.4f kilometers", info, (getPath().getLength() / 1000.0));
if (getInputData().getMode() == Mode.LENGTH) {
info = String.format("%s, %.4f kilometers", info, cost / 1000.0);
}
else {
info = String.format("%s, %.4f minutes", info,
(getPath().getMinimumTravelTime() / 60.0));
info = String.format("%s, %.4f minutes", info, cost / 60.0);
}
}
info += " in " + getSolvingTime().getSeconds() + " seconds.";