     "source": [
      "%%writefile test_bst_validate.py\n",
      "from nose.tools import assert_equal\n",
      "\n",
      "\n",
      "class TestBstValidate(object):\n",
      "\n",
 
</s>
    "from nose.tools import raises\n",
     "source": [
      "%%writefile test_bst_validate.py\n",
      "from nose.tools import assert_equal\n",
    "from nose.tools import raises\n",
      "\n",
      "\n",
      "class TestBstValidate(object):\n",
      "\n",
keep keep add keep keep keep keep
 Polish bst validate challenge and solution (#83)

Update constraints, test cases, tests, algorithm discussion, and code.
graphs_trees/bst_validate/bst_validate_solution.ipynb