1var assert = require('assert');
2
3class Graph {
4  constructor() {
5    this.adjacencyList = new Map();
6  }
7
8  addVertex(nodeVal) {
9    this.adjacencyList.set(nodeVal, []);
10  }
11
12  addEdge(src, dest) {
13    this.adjacencyList.get(src).push(dest);
14    this.adjacencyList.get(dest).push(src);
15  }
16
17  removeVertex(val) {
18    if (this.adjacencyList.get(val)) {
19      this.adjacencyList.delete(val);
20    }
21
22    this.adjacencyList.forEach((vertex) => {
23      const neighborIdx = vertex.indexOf(val);
24      if (neighborIdx >= 0) {
25        vertex.splice(neighborIdx, 1);
26      }
27    });
28  }
29
30  removeEdge(src, dest) {
31    const srcDestIdx = this.adjacencyList.get(src).indexOf(dest);
32    this.adjacencyList.get(src).splice(srcDestIdx, 1);
33
34    const destSrcIdx = this.adjacencyList.get(dest).indexOf(src);
35    this.adjacencyList.get(dest).splice(destSrcIdx, 1);
36  }
37
38  printNeighbors() {
39    const result = [];
40
41    for (let vertex of this.adjacencyList.keys()) {
42      const neighbors = [];
43
44      neighbors.push(`${vertex}:`);
45
46      this.adjacencyList.get(vertex).forEach((neighbor) => {
47        neighbors.push(neighbor);
48      });
49
50      result.push(neighbors.join(' '));
51    }
52
53    return result;
54  }
55}
56
57try {
58  var graph = new Graph(7);
59  var vertices = ['A', 'B', 'C', 'D', 'E', 'F', 'G'];
60  for (var i = 0; i < vertices.length; i++) {
61    graph.addVertex(vertices[i]);
62  }
63  graph.addEdge('A', 'G');
64  graph.addEdge('A', 'E');
65  graph.addEdge('A', 'C');
66  graph.addEdge('B', 'C');
67  graph.addEdge('C', 'D');
68  graph.addEdge('D', 'E');
69  graph.addEdge('E', 'F');
70  graph.addEdge('E', 'C');
71  graph.addEdge('G', 'D');
72  assertSameMembers(graph.printNeighbors(), [
73    'A: G E C',
74    'B: C',
75    'C: A B D E',
76    'D: C E G',
77    'E: A D F C',
78    'F: E',
79    'G: A D',
80  ]);
81
82  console.log(
83    'PASSED: ' + 'Instantiating a graph with several edges and vertices'
84  );
85} catch (err) {
86  console.log(err);
87}
88
89try {
90  graph.removeVertex('A');
91  assertSameMembers(
92    graph.printNeighbors(),
93    ['B: C', 'C: B D E', 'D: C E G', 'E: D F C', 'F: E', 'G: D'],
94    "Removing `A` should return [ 'B: C', 'C: B D E', 'D: C E G', 'E: D F C', 'F: E', 'G: D' ]"
95  );
96
97  console.log('PASSED: ' + 'Removing a vertex');
98} catch (err) {
99  console.log(err);
100}
101
102function assertSameMembers(a, b) {
103  return JSON.stringify(a.sort()) === JSON.stringify(b.sort());
104}