Saved tree height challenge solution so it can be reused as a component to other related challenges.

graphs_trees/tree_height/height.py

@@ -0,0 +1,5 @@
+def height(node):
+    if node is None:
+        return 0
+    return 1 + max(height(node.left), 
+                   height(node.right))

graphs_trees/tree_height/height_solution.ipynb

@@ -89,8 +89,17 @@
    "metadata": {
     "collapsed": false
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Writing height.py\n"
+     ]
+    }
+   ],
    "source": [
+    "%%writefile height.py\n",
     "def height(node):\n",
     "    if node is None:\n",
     "        return 0\n",
@@ -98,6 +107,17 @@
     "                   height(node.right))"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "%run height.py"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -107,7 +127,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 4,
    "metadata": {
     "collapsed": false
    },
@@ -150,7 +170,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 5,
    "metadata": {
     "collapsed": false
    },