Refactor Floyd-Warshall tests.

Author: trekhleb

src/algorithms/graph/floyd-warshall/__test__/floydWarshall.test.js

@@ -55,7 +55,7 @@ describe('floydWarshall', () =>{
 .addEdge(edgeFG)
 .addEdge(edgeEG);
 
-const{ distances,previousVertices}=floydWarshall(graph);
+const{ distances,nextVertices}=floydWarshall(graph);
 
 constvertices=graph.getAllVertices();
 
@@ -77,13 +77,13 @@ describe('floydWarshall', () =>{
 expect(distances[vertexAIndex][vertexGIndex]).toBe(12);
 expect(distances[vertexAIndex][vertexFIndex]).toBe(11);
 
-expect(previousVertices[vertexAIndex][vertexFIndex]).toBe(vertexD);
-expect(previousVertices[vertexAIndex][vertexDIndex]).toBe(vertexB);
-expect(previousVertices[vertexAIndex][vertexBIndex]).toBe(vertexA);
-expect(previousVertices[vertexAIndex][vertexGIndex]).toBe(vertexE);
-expect(previousVertices[vertexAIndex][vertexCIndex]).toBe(vertexA);
-expect(previousVertices[vertexAIndex][vertexAIndex]).toBe(null);
-expect(previousVertices[vertexAIndex][vertexHIndex]).toBe(null);
+expect(nextVertices[vertexAIndex][vertexFIndex]).toBe(vertexD);
+expect(nextVertices[vertexAIndex][vertexDIndex]).toBe(vertexB);
+expect(nextVertices[vertexAIndex][vertexBIndex]).toBe(vertexA);
+expect(nextVertices[vertexAIndex][vertexGIndex]).toBe(vertexE);
+expect(nextVertices[vertexAIndex][vertexCIndex]).toBe(vertexA);
+expect(nextVertices[vertexAIndex][vertexAIndex]).toBe(null);
+expect(nextVertices[vertexAIndex][vertexHIndex]).toBe(null);
 });
 
 it('should find minimum paths to all vertices for directed graph',()=>{
@@ -119,7 +119,7 @@ describe('floydWarshall', () =>{
 .addEdge(edgeCA)
 .addEdge(edgeCD);
 
-const{ distances,previousVertices}=floydWarshall(graph);
+const{ distances,nextVertices}=floydWarshall(graph);
 
 constvertices=graph.getAllVertices();
 
@@ -140,11 +140,11 @@ describe('floydWarshall', () =>{
 [2,5,7,0],
 ]);
 
-expect(previousVertices[vertexAIndex][vertexDIndex]).toBe(vertexC);
-expect(previousVertices[vertexAIndex][vertexCIndex]).toBe(vertexB);
-expect(previousVertices[vertexBIndex][vertexDIndex]).toBe(vertexC);
-expect(previousVertices[vertexAIndex][vertexAIndex]).toBe(null);
-expect(previousVertices[vertexAIndex][vertexBIndex]).toBe(vertexA);
+expect(nextVertices[vertexAIndex][vertexDIndex]).toBe(vertexC);
+expect(nextVertices[vertexAIndex][vertexCIndex]).toBe(vertexB);
+expect(nextVertices[vertexBIndex][vertexDIndex]).toBe(vertexC);
+expect(nextVertices[vertexAIndex][vertexAIndex]).toBe(null);
+expect(nextVertices[vertexAIndex][vertexBIndex]).toBe(vertexA);
 });
 
 it('should find minimum paths to all vertices for directed graph with negative edge weights',()=>{
@@ -188,7 +188,7 @@ describe('floydWarshall', () =>{
 .addEdge(edgeCB)
 .addEdge(edgeBA);
 
-const{ distances,previousVertices}=floydWarshall(graph);
+const{ distances,nextVertices}=floydWarshall(graph);
 
 constvertices=graph.getAllVertices();
 
@@ -208,11 +208,13 @@ describe('floydWarshall', () =>{
 expect(distances[vertexFIndex][vertexDIndex]).toBe(9);
 expect(distances[vertexFIndex][vertexEIndex]).toBe(8);
 
-expect(previousVertices[vertexFIndex][vertexGIndex]).toBe(null);
-expect(previousVertices[vertexFIndex][vertexFIndex]).toBe(null);
-// expect(previousVertices[vertexFIndex][vertexBIndex]).toBe(vertexC);
-// expect(previousVertices[vertexFIndex][vertexCIndex].getKey()).toBe(vertexA.getKey());
-// expect(previousVertices[vertexFIndex][vertexAIndex]).toBe(vertexD);
-// expect(previousVertices[vertexFIndex][vertexDIndex]).toBe(vertexE);
+expect(nextVertices[vertexFIndex][vertexGIndex]).toBe(null);
+expect(nextVertices[vertexFIndex][vertexFIndex]).toBe(null);
+expect(nextVertices[vertexAIndex][vertexBIndex]).toBe(vertexC);
+expect(nextVertices[vertexAIndex][vertexCIndex]).toBe(vertexA);
+expect(nextVertices[vertexFIndex][vertexBIndex]).toBe(vertexE);
+expect(nextVertices[vertexEIndex][vertexBIndex]).toBe(vertexD);
+expect(nextVertices[vertexDIndex][vertexBIndex]).toBe(vertexC);
+expect(nextVertices[vertexCIndex][vertexBIndex]).toBe(vertexC);
 });
 });

src/algorithms/graph/floyd-warshall/floydWarshall.js

@@ -1,14 +1,14 @@
 /**
  * @param{Graph} graph
- * @return{{distances: number[][], previousVertices: GraphVertex[][]}}
+ * @return{{distances: number[][], nextVertices: GraphVertex[][]}}
  */
 exportdefaultfunctionfloydWarshall(graph){
 // Get all graph vertices.
 constvertices=graph.getAllVertices();
 
 // Init previous vertices matrix with nulls meaning that there are no
 // previous vertices exist that will give us shortest path.
-constpreviousVertices=Array(vertices.length).fill(null).map(()=>{
+constnextVertices=Array(vertices.length).fill(null).map(()=>{
 returnArray(vertices.length).fill(null);
 });
 
@@ -33,7 +33,7 @@ export default function floydWarshall(graph){
 // There is an edge from vertex with startIndex to vertex with endIndex.
 // Save distance and previous vertex.
 distances[startIndex][endIndex]=edge.weight;
-previousVertices[startIndex][endIndex]=startVertex;
+nextVertices[startIndex][endIndex]=startVertex;
 }else{
 distances[startIndex][endIndex]=Infinity;
 }
@@ -60,13 +60,13 @@ export default function floydWarshall(graph){
 if(distances[startIndex][endIndex]>distViaMiddle){
 // We've found a shortest pass via middle vertex.
 distances[startIndex][endIndex]=distViaMiddle;
-previousVertices[startIndex][endIndex]=middleVertex;
+nextVertices[startIndex][endIndex]=middleVertex;
 }
 });
 });
 });
 
 // Shortest distance from x to y: distance[x][y].
-// Previous vertex of shortest path from x to y: previousVertices[x][y].
-return{ distances,previousVertices};
+// Next vertex after x one in path from x to y: nextVertices[x][y].
+return{ distances,nextVertices};
 }