Dijkstra的算法应该返回什么

我是一名前端Javascript开发人员，但想学习一些图论来准备Google面试，我查找了Dijkstra算法的一些实现。

此处列出的示例https://github.com/mburst/dijkstras-algorithm/blob/master/dijkstras.js似乎适合找到两个节点之间的最短路径并返回它们之间的最短节点路径，但维基百科上的伪代码版本似乎同时返回"prev和dist"---它们应该是什么？

我尝试修改 github 示例以匹配维基百科伪代码，返回距离似乎确实从一开始就为每个示例提供了最短的数字距离顶点...但是 Prev 没有返回最短路径

var INFINITY = 1/0;
function PriorityQueue () {
  this._nodes = [];
  this.enqueue = function (priority, key) {
    this._nodes.push({key: key, priority: priority });
    this.sort();
  }
  this.dequeue = function () {
    return this._nodes.shift().key;
  }
  this.sort = function () {
    this._nodes.sort(function (a, b) {
      return a.priority - b.priority;
    });
  }
  this.isEmpty = function () {
    return !this._nodes.length;
  }
}

function Graph(){
  this.vertices = {};
  this.addVertex = function(name, edges){
    edges = edges || null;
    this.vertices[name] = edges;
  }
}

function djikstra(graph, startVertex) {
  var nodes = new PriorityQueue();
  var distances = {};
  var previous = {};
  for(vertex in graph.vertices) {
    if (vertex === startVertex) {
      distances[vertex] = 0;
      nodes.enqueue(0, vertex);
    } else {
      distances[vertex] = INFINITY;
      nodes.enqueue(INFINITY, vertex);
    }
    previous[vertex] = null;
  }

  while(!nodes.isEmpty()) {
    var smallest = nodes.dequeue();
    for(var neighbor in graph.vertices[smallest]) {
      var alt = distances[smallest] + graph.vertices[smallest][neighbor];
      if(alt < distances[neighbor]) {
        distances[neighbor] = alt;
        previous[neighbor] = smallest;
      }
    }
  }
  return distances;
}
var graph = new Graph();
graph.addVertex('S', {V: 1, W: 4});
graph.addVertex('V', {W: 2, T: 6});
graph.addVertex('W', {T: 3});
graph.addVertex('T');

console.log(djikstra(graph, 'S'));
//
{ S: 0, V: 1, W: 3, T: 6 }