graph. stack, and queue structures

Graph.js

function Graph(nodes) {
  this.nodes = nodes || {};
}

Graph.prototype.print = function(storage, start, stop) {
  start = start || 1;
  storage.put(new Node(start));

  while (! storage.isEmpty()) {
    var seen = {};
    var from = storage.get();
    var to = this.nodes[from.value];

    if (to) {
      for (var i = 0; i < to.length; i++) {
        if (to[i] == stop) {
          return this.getPath(new Node(to[i], from));
        } else if (! seen[to[i]]) {
          storage.put(new Node(to[i], from));
          seen[to[i]] = true;
        } else {
        }
      }
    }
  }
};

Graph.prototype.getPath = function(finalNode) {
  var node = finalNode;
  var path = [];
  while (node.parent) {
    path.push(node.value);
    node = node.parent;
  }
  return path.reverse();
};

function Node(value, parent, weight) {
  this.value = value;
  this.parent = parent || true;
  this.weight = weight || 1;
}

var graph1 = {
  1: [2, 4],
  2: [1, 3, 5],
  3: [2],
  4: [7, 1],
  5: [2, 6, 8],
  6: [5, 9, 10],
  7: [4],
  8: [5],
  9: [6, 12],
  10: [6, 11],
  11: [10]
};

var graph2 = {
  1: [2, 4],
  2: [1, 3, 5],
  3: [2, 11],
  4: [1, 5, 7],
  5: [2, 4, 6, 8],
  6: [5, 9, 10],
  7: [4, 13],
  8: [5, 14],
  9: [6, 12],
  10: [6, 11],
  11: [3 ,10],
  12: [9],
  13: [7, 14],
  14: [8, 13]
};

var graph = new Graph(graph2);

console.log('queue 1 -> 14');
out = graph.print(new Queue(), 1, 14); // breadth-first search
console.log(out);
console.log('stack 1 -> 14');
out = graph.print(new Stack(), 1, 14); // depth-first search
console.log(out);

Queue.js

function Queue() {
  this.elements = [];
}

Queue.prototype = {
  get: function() {
    return this.elements.shift();
  },

  put: function(element) {
    return this.elements.push(element);
  },

  size: function() {
    return this.elements.length;
  },

  isEmpty: function() {
    return this.size() === 0;
  }
};

module.exports = Queue;

Stack.js

function Stack() {
  this.elements = [];
}

Stack.prototype = {
  get: function() {
    return this.elements.pop();
  },

  put: function(element) {
    return this.elements.push(element);
  },

  size: function() {
    return this.elements.length;
  },

  isEmpty: function() {
    return this.size() === 0;
  }
};