Graph_methods.js

class Graph {
  constructor() {
    this.AdjList = new Map();
  }
  
  addVertex(vertex) {
    if (!this.AdjList.has(vertex)) {
      this.AdjList.set(vertex, []);
    } else {
      throw 'Already Exist!!!';
    }
  }
  
  addEdge(vertex, node) {
    if (this.AdjList.has(vertex)) {
      if (this.AdjList.has(node)){
        let arr = this.AdjList.get(vertex);
        if(!arr.includes(node)){
          arr.push(node);
        }
      }else {
        throw `Can't add non-existing vertex ->'${node}'`;
      }
    } else {
      throw `You should add '${vertex}' first`;
    }
  }
  
  print() {
    for (let [key, value] of this.AdjList) {
      console.log(key, value);
    }
  }
}