     "source": [
      "## Constraints\n",
      "\n",
      "* Is the graph directed?\n",
      "    * Yes\n",
      "* Do the edges have weights?\n",
      "    * Yes"
     ]
    },
    {
 
</s>
    "    * Implement both\n",
     "source": [
      "## Constraints\n",
      "\n",
      "* Is the graph directed?\n",
    "    * Implement both\n",
      "* Do the edges have weights?\n",
      "    * Yes"
     ]
    },
    {
keep keep keep keep replace keep keep keep keep keep
 Rework graph challenge and solution (#86)
graphs_trees/graph/graph_solution.ipynb