Method addEdge

src/13-graph/graph.js:21–32

(vertex, edge)

  }

  addEdge(vertex, edge) {
    if (!this.#adjList.get(vertex)) {
      this.addVertex(vertex);
    }
    if (!this.#adjList.get(edge)) {
      this.addVertex(edge);
    }
    this.#adjList.get(vertex).push(edge);
    if (!this.#isDirected) {
      this.#adjList.get(edge).push(vertex);
    }
  }

  get vertices() {
    return this.#vertices;