weightFunction to calculate weight of path ...

src/algorithms/shortestPath/getPath.ts

@@ -3,6 +3,13 @@ import type { TraversingTracks } from './types.js';
 
 import { Graph } from '../../Graph.js';
 
+export function addWeightFunction(edgeWeight: number, currentPathWeight: number | undefined, hop: number): number {
+  if (currentPathWeight === undefined) {
+      return edgeWeight;
+  }
+  return edgeWeight + currentPathWeight;
+}
+
 /**
  * Assembles the shortest path by traversing the
  * predecessor subgraph from destination to source.
@@ -12,22 +19,25 @@ export function getPath<Node, LinkProps>(
   tracks: TraversingTracks<NoInfer<Node>>,
   source: NoInfer<Node>,
   destination: NoInfer<Node>,
+  weightFunction: (edgeWeight: number, currentPathWeight: number, hop: number) => number = addWeightFunction
 ): {
   nodes: [Node, Node, ...Node[]];
   weight: number;
 } {
   const { p } = tracks;
   const nodeList: Node[] & { weight?: EdgeWeight } = [];
 
-  let totalWeight = 0;
+  let totalWeight = undefined as unknown as EdgeWeight;
   let node = destination;
 
+  let hop = 1;
   while (p.has(node)) {
     const currentNode = p.get(node)!;
 
     nodeList.push(node);
-    totalWeight += graph.getEdgeWeight(currentNode, node);
+    totalWeight = weightFunction(graph.getEdgeWeight(currentNode, node), totalWeight, hop);
     node = currentNode;
+    hop++;
   }
 
   if (node !== source) {

src/algorithms/shortestPath/shortestPath.ts

@@ -1,7 +1,7 @@
 import { Graph } from '../../Graph.js';
 import { NoInfer } from '../../types.js';
 import { dijkstra } from './dijkstra.js';
-import { getPath } from './getPath.js';
+import { getPath, addWeightFunction } from './getPath.js';
 import { TraversingTracks } from './types.js';
 
 /**
@@ -13,6 +13,7 @@ export function shortestPath<Node, LinkProps>(
   graph: Graph<Node, LinkProps>,
   source: NoInfer<Node>,
   destination: NoInfer<Node>,
+  weightFunction: (edgeWeight: number, currentPathWeight: number, hop: number) => number = addWeightFunction
 ): {
   nodes: [Node, Node, ...Node[]];
   weight: number;
@@ -25,5 +26,5 @@ export function shortestPath<Node, LinkProps>(
 
   dijkstra(graph, tracks, source, destination);
 
-  return getPath(graph, tracks, source, destination);
+  return getPath(graph, tracks, source, destination, weightFunction);
 }