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few fixes: dijkstra

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This commit is contained in:
Clement Lacau 2024-04-18 01:05:14 +02:00
parent 4bd0c74fa4
commit f51d3a26b5
2 changed files with 43 additions and 19 deletions
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52
be-graphes-algos/src/main/java/org/insa/graphs/algorithm/shortestpath/DijkstraAlgorithm.java
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@ -21,7 +21,7 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
// TODO:
// Heap of "sommets"
BinaryHeap<Label> queue = new BinaryHeap<Label>(); // change to a comparable type
BinaryHeap<Label> labels = new BinaryHeap<Label>(); // change to a comparable type
Graph graph = data.getGraph();
final int nbNodes = graph.size();
@ -35,41 +35,65 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
notifyOriginProcessed(data.getOrigin());
// Init Dijkstra
ArrayList<Label> labels = new ArrayList<Label>();
//ArrayList<Label> labels = new ArrayList<Label>();
for (Node node : graph.getNodes()) {
labels.add(new Label(node));
labels.insert(new Label(node));
}
// Nodes set
for (Label label : labels) {
for (Label label : labels.array) {
label.marked = false;
label.setPathCost(Float.MAX_VALUE);
label.parentNode = null;
}
// Origin set
Label s = labels.get(0);
Label s = labels.array.get(0);
s.setPathCost(0);
queue.insert(s);
labels.insert(s);
boolean trouve = false; // TODO : breaking condition
Label x;
while (!queue.isEmpty() && !trouve) {
x = queue.ExtractMin();
while (!labels.isEmpty() && !trouve) {
x = labels.deleteMin();
x.mark();
for (Arc arc : x.node.getSuccessors()) {
// TODO : Retrieve label with node
Label y;
if (!arc.getDestination().marked) {
float new_cost = x.getCost() + (float) data.getCost(arc);
// y shall be all the successors of x
float arc_cost = 0;
for (Label y : labels.array) {
if (y.getParentNode() == x.getNode()) {
if (y.isMarked()) {
// This loop serves to get the lentgh of the arc as
// we know its origin and destination
for (Arc arc : x.getNode().getSuccessors()) {
if (y.getNode() == arc.getDestination()) {
arc_cost = arc.getLength();
}
}
float new_cost = x.getCost() + arc_cost;
if (y.getCost() > new_cost) {
y.setPathCost(new_cost);
queue.insert(y);
labels.insert(y);
y.setParentNode(x.getNode());
}
}
}
}
}
// Create the path ...
ArrayList<Arc> arcs_path = new ArrayList<>();
Label dest;
for (Label label : labels.array) {
if (label.getNode() == data.getDestination()){
dest = label;
}
}
Node current = dest.getParentNode();
while (current != null) {
current
}
arc = predecessorArcs[arc.getOrigin().getId()];
}
return solution;
}

2
be-graphes-algos/src/main/java/org/insa/graphs/algorithm/utils/BinaryHeap.java
View file

@ -17,7 +17,7 @@ public class BinaryHeap<E extends Comparable<E>> implements PriorityQueue<E> {
private int currentSize;
// The heap array, which can be larger than currentSize.
protected final ArrayList<E> array;
public final ArrayList<E> array;
/**
* Construct a new empty binary heap.