Dijkstra算法，尝试在最短路径中找到第一个节点

Question

我一直在这个问题上停留，没有取得任何进展。我想以成功的“最短路径”遍历（ala Dijkstra的算法）查找并打印出FIRST节点。如在第一个选择访问指定节点的路径中。我觉得我需要一个数据结构，也许是一个ArrayList？我已经尝试过了，但是我似乎无法将它作为经过的节点的简明清单。

我的代码：

    public static ShortestPaths runDijkstra(Map<String,Node> graph, Node startNode) {
    //Queue for visited nodes
    Queue<Node> unvisitedNodes = new LinkedList<>();

    //Distance of node from source
    Map<Node,Integer> distances = new HashMap<>();
    //Current node w/previous node in optimal path
    Map<Node,Node> previousNode = new HashMap<>();

    for(Node n : graph.values()) {
        //Fill collections
        distances.put(n, Integer.MAX_VALUE);
        previousNode.put(n, null);
        unvisitedNodes.add(n);
    }
    //Set source node distance to 0
    distances.put(startNode, 0);

    while(!unvisitedNodes.isEmpty()) {
        int lowestDistance = Integer.MAX_VALUE;
        Node current = null;
        for(Node n : unvisitedNodes) {
            if(distances.get(n) < lowestDistance) {
                lowestDistance = distances.get(n);
                current = n;
            }
        }

        unvisitedNodes.remove(current);

        for(Entry<Node,Integer> neighborEntry : current.adjacentNodes.entrySet()) {
            int distanceFromNeighborToSource = (distances.get(current) + neighborEntry.getValue());
            Node neighbor = neighborEntry.getKey();
            if(distanceFromNeighborToSource < distances.get(neighborEntry.getKey())) {
                distances.put(neighbor, distanceFromNeighborToSource);
                previousNode.put(neighbor, current);
            }
        }

    }

    previousNode.put(startNode, new Node("-"));

    return new ShortestPaths(distances, previousNode);

}