     "metadata": {},
     "source": [
      "## Test Cases\n",
      "\n",
      "### Breadth-First Search\n",
      "* 5, 2, 8, 1, 3 -> 5, 2, 8, 1, 3"
     ]
    },
    {
     "cell_type": "markdown",
 
</s>
    "### Breadth-First Traversal\n",
     "metadata": {},
     "source": [
      "## Test Cases\n",
      "\n",
    "### Breadth-First Traversal\n",
      "* 5, 2, 8, 1, 3 -> 5, 2, 8, 1, 3"
     ]
    },
    {
     "cell_type": "markdown",
keep keep keep keep replace keep keep keep keep keep
 Polish tree bfs challenge and solution (#77)

Update constraints and algorithm discussion.
graphs_trees/tree_bfs/bfs_solution.ipynb