bfs-adj.js

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

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

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

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


/* 
An undirected graph. Print out each node and it's distance from the source
    A
  /	   \
  B     C
        /   \
       D     E

*/

var graph = {
	"A": ["B","C"], 
	"B": [],
	"C": ["D","E"],
	"D": [],
	"E":[]	
};
var nodeNotVisited = (list,item) => {
	if (list.indexOf(item) === -1) {
		return true;
	}
	return false;
};
// write a bfs function that returns an array of the vertices as they were visited

var bfs = (graph,node) => {
  let visitedNodes = [];
  let q = new Queue();
  q.enq(node);
  visitedNodes.push(node);
  
  while(!q.isEmpty()){
    let currentNode = q.deq();
    console.log(currentNode);
    let neighbors = graph[currentNode];
    
    if(neighbors.length > 0){
      neighbors.forEach((neighbor) => { 
        if (nodeNotVisited(visitedNodes,neighbor)) {
	  visitedNodes.push(neighbor);
          q.enq(neighbor);
        }    
      });
    }
  }
  return visitedNodes;
};


bfs(graph,"A");