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  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Nodes and References Implementation of a Tree\n",
    "\n",
    "In this notebook is the code corresponding to the lecture for implementing the representation of a Tree as a class with nodes and references!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "class BinaryTree(object):\n",
    "    def __init__(self,rootObj):\n",
    "        self.key = rootObj\n",
    "        self.leftChild = None\n",
    "        self.rightChild = None\n",
    "\n",
    "    def insertLeft(self,newNode):\n",
    "        if self.leftChild == None:\n",
    "            self.leftChild = BinaryTree(newNode)\n",
    "        else:\n",
    "            t = BinaryTree(newNode)\n",
    "            t.leftChild = self.leftChild\n",
    "            self.leftChild = t\n",
    "\n",
    "    def insertRight(self,newNode):\n",
    "        if self.rightChild == None:\n",
    "            self.rightChild = BinaryTree(newNode)\n",
    "        else:\n",
    "            t = BinaryTree(newNode)\n",
    "            t.rightChild = self.rightChild\n",
    "            self.rightChild = t\n",
    "\n",
    "\n",
    "    def getRightChild(self):\n",
    "        return self.rightChild\n",
    "\n",
    "    def getLeftChild(self):\n",
    "        return self.leftChild\n",
    "\n",
    "    def setRootVal(self,obj):\n",
    "        self.key = obj\n",
    "\n",
    "    def getRootVal(self):\n",
    "        return self.key"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can see some examples of creating a tree and assigning children. Note that some outputs are Trees themselves!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "a\n",
      "None\n",
      "<__main__.BinaryTree object at 0x104779c10>\n",
      "b\n",
      "<__main__.BinaryTree object at 0x103b42c50>\n",
      "c\n",
      "hello\n"
     ]
    }
   ],
   "source": [
    "from __future__ import print_function\n",
    "\n",
    "r = BinaryTree('a')\n",
    "print(r.getRootVal())\n",
    "print(r.getLeftChild())\n",
    "r.insertLeft('b')\n",
    "print(r.getLeftChild())\n",
    "print(r.getLeftChild().getRootVal())\n",
    "r.insertRight('c')\n",
    "print(r.getRightChild())\n",
    "print(r.getRightChild().getRootVal())\n",
    "r.getRightChild().setRootVal('hello')\n",
    "print(r.getRightChild().getRootVal())"
   ]
  }
 ],
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