Renames, initialize distances to Infinity, remove external link

Author: caojoshua

graph/dijkstra.ts

@@ -11,8 +11,8 @@
  */
 export const dijkstra = (graph: number[][], start: number): number[] => {
   let visited = Array(graph.length).fill(false);
-  let paths = Array(graph.length).fill(Number.MAX_SAFE_INTEGER);
-  paths[start] = 0;
+  let distances = Array(graph.length).fill(Infinity);
+  distances[start] = 0;
 
   let node = start;
   while (node !== -1) {
@@ -21,15 +21,15 @@ export const dijkstra = (graph: number[][], start: number): number[] => {
       if (child == node || weight === 0) {
         return;
       }
-      let new_path = paths[node] + weight;
-      if (new_path < paths[child]) {
-        paths[child] = new_path;
+      let new_path = distances[node] + weight;
+      if (new_path < distances[child]) {
+        distances[child] = new_path;
       }
     });
-    node = extract_min(paths, visited);
+    node = extract_min(distances, visited);
   }
 
-  return paths;
+  return distances;
 }
 
 const extract_min = (paths: number[], visited: boolean[]): number => {

graph/test/dijkstra.test.ts

@@ -16,7 +16,6 @@ describe("dijkstra", () => {
   }
 
   it("should return the correct value", () => {
-    // Example from https://www.geeksforgeeks.org/dijkstras-shortest-path-algorithm-greedy-algo-7/
     let graph = init_graph(9);
     add_edge(graph, 0, 1, 4);
     add_edge(graph, 0, 7, 8);
@@ -54,8 +53,7 @@ describe("dijkstra", () => {
 
   let unreachable_graph = init_graph(3);
   add_edge(unreachable_graph, 0, 1, 1);
-  const m = Number.MAX_SAFE_INTEGER
-  test.each([[0, [0, 1, m]], [1, [1, 0, m]], [2, [m, m, 0]]])(
+  test.each([[0, [0, 1, Infinity]], [1, [1, 0, Infinity]], [2, [Infinity, Infinity, 0]]])(
     "correct result for graph with unreachable nodes with source node %i",
     (source, result) => {
       expect(dijkstra(unreachable_graph, source)).toStrictEqual(result);