Graphs: breadth-first search

graphs.js

/* Graphs: Breadth-first search */

function bfs(graph, root) {
  var nodesLen = {};
  
  for (var i = 0; i < graph.length; i++) {
    nodesLen[i] = Infinity;
  }
  nodesLen[root] = 0; 
  
  var queue = [root]; 
  var current; 

  while (queue.length != 0) {
    current = queue.shift();
    
    var curConnected = graph[current];
    var neighborIdx = []; 
    var idx = curConnected.indexOf(1); 
    while (idx != -1) {
      neighborIdx.push(idx); 
      idx = curConnected.indexOf(1, idx + 1); 
    }
    
    for (var j = 0; j < neighborIdx.length; j++) {
      if (nodesLen[neighborIdx[j]] == Infinity) {
        nodesLen[neighborIdx[j]] = nodesLen[current] + 1;
        queue.push(neighborIdx[j]); 
      }
    }
  }
  return nodesLen;
};

var exBFSGraph = [
  [0, 1, 1, 1, 0],
  [0, 0, 1, 0, 0],
  [1, 1, 0, 0, 0],
  [0, 0, 0, 1, 0],
  [0, 1, 0, 0, 0]
];
console.log(bfs(exBFSGraph, 1));