dist-javascript-algorithms-and-data-structures/dist/algorithms/graph/dijkstra/__test__/dijkstra.test.js

Algorithms and data-structures implemented on JavaScript

"use strict";

var _GraphVertex = _interopRequireDefault(require("../../../../data-structures/graph/GraphVertex"));

var _GraphEdge = _interopRequireDefault(require("../../../../data-structures/graph/GraphEdge"));

var _Graph = _interopRequireDefault(require("../../../../data-structures/graph/Graph"));

var _dijkstra = _interopRequireDefault(require("../dijkstra"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

describe('dijkstra', () => {
  it('should find minimum paths to all vertices for undirected graph', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const vertexD = new _GraphVertex.default('D');
    const vertexE = new _GraphVertex.default('E');
    const vertexF = new _GraphVertex.default('F');
    const vertexG = new _GraphVertex.default('G');
    const vertexH = new _GraphVertex.default('H');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB, 4);
    const edgeAE = new _GraphEdge.default(vertexA, vertexE, 7);
    const edgeAC = new _GraphEdge.default(vertexA, vertexC, 3);
    const edgeBC = new _GraphEdge.default(vertexB, vertexC, 6);
    const edgeBD = new _GraphEdge.default(vertexB, vertexD, 5);
    const edgeEC = new _GraphEdge.default(vertexE, vertexC, 8);
    const edgeED = new _GraphEdge.default(vertexE, vertexD, 2);
    const edgeDC = new _GraphEdge.default(vertexD, vertexC, 11);
    const edgeDG = new _GraphEdge.default(vertexD, vertexG, 10);
    const edgeDF = new _GraphEdge.default(vertexD, vertexF, 2);
    const edgeFG = new _GraphEdge.default(vertexF, vertexG, 3);
    const edgeEG = new _GraphEdge.default(vertexE, vertexG, 5);
    const graph = new _Graph.default();
    graph.addVertex(vertexH).addEdge(edgeAB).addEdge(edgeAE).addEdge(edgeAC).addEdge(edgeBC).addEdge(edgeBD).addEdge(edgeEC).addEdge(edgeED).addEdge(edgeDC).addEdge(edgeDG).addEdge(edgeDF).addEdge(edgeFG).addEdge(edgeEG);
    const {
      distances,
      previousVertices
    } = (0, _dijkstra.default)(graph, vertexA);
    expect(distances).toEqual({
      H: Infinity,
      A: 0,
      B: 4,
      E: 7,
      C: 3,
      D: 9,
      G: 12,
      F: 11
    });
    expect(previousVertices.F.getKey()).toBe('D');
    expect(previousVertices.D.getKey()).toBe('B');
    expect(previousVertices.B.getKey()).toBe('A');
    expect(previousVertices.G.getKey()).toBe('E');
    expect(previousVertices.C.getKey()).toBe('A');
    expect(previousVertices.A).toBeNull();
    expect(previousVertices.H).toBeNull();
  });
  it('should find minimum paths to all vertices for directed graph with negative edge weights', () => {
    const vertexS = new _GraphVertex.default('S');
    const vertexE = new _GraphVertex.default('E');
    const vertexA = new _GraphVertex.default('A');
    const vertexD = new _GraphVertex.default('D');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const vertexH = new _GraphVertex.default('H');
    const edgeSE = new _GraphEdge.default(vertexS, vertexE, 8);
    const edgeSA = new _GraphEdge.default(vertexS, vertexA, 10);
    const edgeED = new _GraphEdge.default(vertexE, vertexD, 1);
    const edgeDA = new _GraphEdge.default(vertexD, vertexA, -4);
    const edgeDC = new _GraphEdge.default(vertexD, vertexC, -1);
    const edgeAC = new _GraphEdge.default(vertexA, vertexC, 2);
    const edgeCB = new _GraphEdge.default(vertexC, vertexB, -2);
    const edgeBA = new _GraphEdge.default(vertexB, vertexA, 1);
    const graph = new _Graph.default(true);
    graph.addVertex(vertexH).addEdge(edgeSE).addEdge(edgeSA).addEdge(edgeED).addEdge(edgeDA).addEdge(edgeDC).addEdge(edgeAC).addEdge(edgeCB).addEdge(edgeBA);
    const {
      distances,
      previousVertices
    } = (0, _dijkstra.default)(graph, vertexS);
    expect(distances).toEqual({
      H: Infinity,
      S: 0,
      A: 5,
      B: 5,
      C: 7,
      D: 9,
      E: 8
    });
    expect(previousVertices.H).toBeNull();
    expect(previousVertices.S).toBeNull();
    expect(previousVertices.B.getKey()).toBe('C');
    expect(previousVertices.C.getKey()).toBe('A');
    expect(previousVertices.A.getKey()).toBe('D');
    expect(previousVertices.D.getKey()).toBe('E');
  });
});