bfs-2.js

class Queue {
    constructor() {
        this.items = [];
    }

    enq(obj) {
        this.items.push(obj);
    }

    deq() {
        return this.items.shift();
    }

    isEmpty() {
        return this.items.length === 0;
    }
}


class Node{
  constructor(value,children=[]){
    this.value       = value;
    this.children    = children;
    this.distance    = null;
  }
}



var node5 = new Node(5);
var node4 = new Node(4);
var node3 = new Node(3, [node4, node5]);
var node2 = new Node(2);
var node1 = new Node(1, [node2, node3]);



var bfs = (node) => {
  var q = new Queue();
  q.enq(node);
  node.distance = 0;
  while(!q.isEmpty()){
    var currentNode = q.deq();
    console.log("Node " + currentNode.value + " distance: " + currentNode.distance + " from source.");
      if(currentNode.children.length > 0){
        currentNode.children.forEach((child) => { 
          child.distance = currentNode.distance + 1;
          q.enq(child);
            
        });
      }
  }
};

bfs(node1);