diff --git a/be-graphes-algos/src/main/java/org/insa/graphs/algorithm/shortestpath/DijkstraAlgorithm.java b/be-graphes-algos/src/main/java/org/insa/graphs/algorithm/shortestpath/DijkstraAlgorithm.java
index e731977..ae0cc11 100644
--- a/be-graphes-algos/src/main/java/org/insa/graphs/algorithm/shortestpath/DijkstraAlgorithm.java
+++ b/be-graphes-algos/src/main/java/org/insa/graphs/algorithm/shortestpath/DijkstraAlgorithm.java
@@ -12,6 +12,8 @@ import org.insa.graphs.model.Path;
 
 public class DijkstraAlgorithm extends ShortestPathAlgorithm {
 
+    Label[] labels;
+
     public DijkstraAlgorithm(ShortestPathData data) {
         super(data);
     }
@@ -20,6 +22,12 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
         return new Label(node);
     }
 
+    protected Label getLabel(Node node) {
+        if (labels[node.getId()] == null)
+            labels[node.getId()] = createLabel(node);
+        return labels[node.getId()];
+    }
+
     @Override
     protected ShortestPathSolution doRun() {
 
@@ -31,7 +39,7 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
         final int nbNodes = graph.size();
 
         // List of sommets, but with type Label
-        ArrayList<Label> labels = new ArrayList<Label>(nbNodes);
+        labels = new Label[nbNodes];
 
         // Heap of sommets
         BinaryHeap<Label> tas = new BinaryHeap<Label>();
@@ -39,25 +47,21 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
         // Notify observers about the first event (origin processed).
         notifyOriginProcessed(data.getOrigin());
 
-        // Init Dijkstra
-        for (Node node : graph.getNodes()) {
-            // Luckily they are ordered by id.
-            // ArrayList.set only works if the value is already initialized (because why Java?)
-            labels.add(this.createLabel(node));
-        }
+        // Init Dijkstra : for performance reasons we create labels on the fly,
+        // instead of at initialization
 
-        Label s = labels.get(data.getOrigin().getId());
+        final Label s = getLabel(data.getOrigin());
 
         // Add origin in the heap
-        // Label s = origin;//labels.get(0);
+        // Label s = origin;
         s.setPathCost(0);
         tas.insert(s);
 
         // On considère le sommet x à chaque itération
         Label x = s;
 
-        final int dest_id = data.getDestination().getId();
-        while (!tas.isEmpty() && !(labels.get(dest_id).getNode().equals(x.getNode()))) {
+        final Node dest = data.getDestination();
+        while (!tas.isEmpty() && !(x.getNode().equals(dest))) {
             x = tas.deleteMin();
             x.mark();
             notifyNodeMarked(x.getNode());
@@ -65,7 +69,7 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
             // We create a list of node successors of x, instead of a list of Arcs.
             double arc_cost = 0;
             for (Arc successorArc : x.getNode().getSuccessors()) {
-                Label successor = labels.get(successorArc.getDestination().getId());
+                Label successor = getLabel(successorArc.getDestination());
                 arc_cost = Double.MAX_VALUE;
                 if (!successor.isMarked() && data.isAllowed(successorArc)) {
                     // This loop serves to get the length of the arc as
@@ -101,7 +105,7 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
             }
         }
 
-    if (labels.get(data.getDestination().getId()).getParentArc() == null) {
+    if (getLabel(data.getDestination()).getParentArc() == null) {
         this.pathCost = 0;
         solution = new ShortestPathSolution(data, Status.INFEASIBLE);
     }
@@ -109,13 +113,13 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
         // Create the path ...
         ArrayList<Arc> arcs_path = new ArrayList<>();
 
-        Arc arc = labels.get(data.getDestination().getId()).getParentArc();
+        Arc arc = getLabel(data.getDestination()).getParentArc();
 
         // We will find the path using the parent nodes, from the destination to the
         // origin
         while (arc != null && arc.getDestination().getId() != data.getOrigin().getId()) {
             arcs_path.add(arc);
-            arc = labels.get(arc.getOrigin().getId()).getParentArc();
+            arc = getLabel(arc.getOrigin()).getParentArc();
         }
 
         notifyDestinationReached(data.getDestination());
@@ -126,7 +130,7 @@ public class DijkstraAlgorithm extends ShortestPathAlgorithm {
         // Create the final solution.
         solution = new ShortestPathSolution(data, Status.OPTIMAL, new Path(graph, arcs_path));
 
-        this.pathCost = labels.get(data.getDestination().getId()).getCost();
+        this.pathCost = getLabel(data.getDestination()).getCost();
     }
         return solution;
     }