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JAVA-13615

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GitHub Issue: The code for A* is in the src/test/java directory, not the
src/main/java directory
This commit is contained in:
Ulisses Lima
2022-07-25 12:27:02 -03:00
parent bbb25c7e76
commit 064ea74cde
7 changed files with 0 additions and 0 deletions
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30
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/Graph.java
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@@ -1,30 +0,0 @@
package com.baeldung.algorithms.astar;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
public class Graph<T extends GraphNode> {
private final Set<T> nodes;
private final Map<String, Set<String>> connections;
public Graph(Set<T> nodes, Map<String, Set<String>> connections) {
this.nodes = nodes;
this.connections = connections;
}
public T getNode(String id) {
return nodes.stream()
.filter(node -> node.getId().equals(id))
.findFirst()
.orElseThrow(() -> new IllegalArgumentException("No node found with ID"));
}
public Set<T> getConnections(T node) {
return connections.get(node.getId()).stream()
.map(this::getNode)
.collect(Collectors.toSet());
}
}

5
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/GraphNode.java
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@@ -1,5 +0,0 @@
package com.baeldung.algorithms.astar;
public interface GraphNode {
String getId();
}

69
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/RouteFinder.java
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@@ -1,69 +0,0 @@
package com.baeldung.algorithms.astar;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.stream.Collectors;
import lombok.extern.slf4j.Slf4j;
@Slf4j
public class RouteFinder<T extends GraphNode> {
private final Graph<T> graph;
private final Scorer<T> nextNodeScorer;
private final Scorer<T> targetScorer;
public RouteFinder(Graph<T> graph, Scorer<T> nextNodeScorer, Scorer<T> targetScorer) {
this.graph = graph;
this.nextNodeScorer = nextNodeScorer;
this.targetScorer = targetScorer;
}
public List<T> findRoute(T from, T to) {
Map<T, RouteNode<T>> allNodes = new HashMap<>();
Queue<RouteNode> openSet = new PriorityQueue<>();
RouteNode<T> start = new RouteNode<>(from, null, 0d, targetScorer.computeCost(from, to));
allNodes.put(from, start);
openSet.add(start);
while (!openSet.isEmpty()) {
log.debug("Open Set contains: " + openSet.stream().map(RouteNode::getCurrent).collect(Collectors.toSet()));
RouteNode<T> next = openSet.poll();
log.debug("Looking at node: " + next);
if (next.getCurrent().equals(to)) {
log.debug("Found our destination!");
List<T> route = new ArrayList<>();
RouteNode<T> current = next;
do {
route.add(0, current.getCurrent());
current = allNodes.get(current.getPrevious());
} while (current != null);
log.debug("Route: " + route);
return route;
}
graph.getConnections(next.getCurrent()).forEach(connection -> {
double newScore = next.getRouteScore() + nextNodeScorer.computeCost(next.getCurrent(), connection);
RouteNode<T> nextNode = allNodes.getOrDefault(connection, new RouteNode<>(connection));
allNodes.put(connection, nextNode);
if (nextNode.getRouteScore() > newScore) {
nextNode.setPrevious(next.getCurrent());
nextNode.setRouteScore(newScore);
nextNode.setEstimatedScore(newScore + targetScorer.computeCost(connection, to));
openSet.add(nextNode);
log.debug("Found a better route to node: " + nextNode);
}
});
}
throw new IllegalStateException("No route found");
}
}

67
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/RouteNode.java
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@@ -1,67 +0,0 @@
package com.baeldung.algorithms.astar;
import java.util.StringJoiner;
class RouteNode<T extends GraphNode> implements Comparable<RouteNode> {
private final T current;
private T previous;
private double routeScore;
private double estimatedScore;
RouteNode(T current) {
this(current, null, Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY);
}
RouteNode(T current, T previous, double routeScore, double estimatedScore) {
this.current = current;
this.previous = previous;
this.routeScore = routeScore;
this.estimatedScore = estimatedScore;
}
T getCurrent() {
return current;
}
T getPrevious() {
return previous;
}
double getRouteScore() {
return routeScore;
}
double getEstimatedScore() {
return estimatedScore;
}
void setPrevious(T previous) {
this.previous = previous;
}
void setRouteScore(double routeScore) {
this.routeScore = routeScore;
}
void setEstimatedScore(double estimatedScore) {
this.estimatedScore = estimatedScore;
}
@Override
public int compareTo(RouteNode other) {
if (this.estimatedScore > other.estimatedScore) {
return 1;
} else if (this.estimatedScore < other.estimatedScore) {
return -1;
} else {
return 0;
}
}
@Override
public String toString() {
return new StringJoiner(", ", RouteNode.class.getSimpleName() + "[", "]").add("current=" + current)
.add("previous=" + previous).add("routeScore=" + routeScore).add("estimatedScore=" + estimatedScore)
.toString();
}
}

5
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/Scorer.java
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@@ -1,5 +0,0 @@
package com.baeldung.algorithms.astar;
public interface Scorer<T extends GraphNode> {
double computeCost(T from, T to);
}

19
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/underground/HaversineScorer.java
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@@ -1,19 +0,0 @@
package com.baeldung.algorithms.astar.underground;
import com.baeldung.algorithms.astar.Scorer;
public class HaversineScorer implements Scorer<Station> {
@Override
public double computeCost(Station from, Station to) {
double R = 6372.8; // In kilometers
double dLat = Math.toRadians(to.getLatitude() - from.getLatitude());
double dLon = Math.toRadians(to.getLongitude() - from.getLongitude());
double lat1 = Math.toRadians(from.getLatitude());
double lat2 = Math.toRadians(to.getLatitude());
double a = Math.pow(Math.sin(dLat / 2),2) + Math.pow(Math.sin(dLon / 2),2) * Math.cos(lat1) * Math.cos(lat2);
double c = 2 * Math.asin(Math.sqrt(a));
return R * c;
}
}

42
algorithms-modules/algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/underground/Station.java
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@@ -1,42 +0,0 @@
package com.baeldung.algorithms.astar.underground;
import java.util.StringJoiner;
import com.baeldung.algorithms.astar.GraphNode;
public class Station implements GraphNode {
private final String id;
private final String name;
private final double latitude;
private final double longitude;
public Station(String id, String name, double latitude, double longitude) {
this.id = id;
this.name = name;
this.latitude = latitude;
this.longitude = longitude;
}
@Override
public String getId() {
return id;
}
public String getName() {
return name;
}
public double getLatitude() {
return latitude;
}
public double getLongitude() {
return longitude;
}
@Override
public String toString() {
return new StringJoiner(", ", Station.class.getSimpleName() + "[", "]").add("id='" + id + "'")
.add("name='" + name + "'").add("latitude=" + latitude).add("longitude=" + longitude).toString();
}
}