Précisions exercice 2

exercice2.md

@@ -60,11 +60,28 @@ MATCH (p:Point) DETACH DELETE p;
 
 2. Quel est le plus court chemin entre le casino et la falaise
 
-a. Un chemin comportant au maximum 10 segments (mais ce n'est pas le plus court !)
+a. Un chemin comportant au maximum 8 segments (mais ce n'est pas le plus court !)
 
 ![](route.png)
 
+Utilisation de la fonction dijkstra de la bibliothèque GDS
 
+[49, 54, 46, 28, 45, 24, 23, 13, 6, 7, 2, 1, 8, 9, 18, 19, 20, 57, 21, 31, 38, 39, 40, 58]
+
+```cypher
+MATCH (source:Point {id: 49}), (target:Point {id: 58})
+CALL gds.shortestPath.dijkstra.stream('routes_graph', {
+  sourceNode: source,
+  targetNode: target,
+  relationshipWeightProperty: 'cout'
+})
+YIELD nodeIds, totalCost
+UNWIND range(0, size(nodeIds)-2) AS i
+MATCH (n1) WHERE id(n1) = nodeIds[i]
+MATCH (n2) WHERE id(n2) = nodeIds[i+1]
+MATCH path = (n1)-[r:ROUTE]->(n2)
+RETURN collect(path) AS chemin, totalCost;
+```
 
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