mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
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284 lines
8.1 KiB
Plaintext
284 lines
8.1 KiB
Plaintext
{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"<small><i>This notebook was prepared by Marco Guajardo. Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).</i></small>"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Challenge Notebook"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Problem: Implement a binary search tree with insert, delete, different traversals & max/min node values\n",
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"* [Constraints](#Constraints)\n",
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"* [Test Cases](#Test-Cases)\n",
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"* [Algorithm](#Algorithm)\n",
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"* [Code](#Code)\n",
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"* [Unit Test](#Unit-Test)\n",
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"* [Solution Notebook](#Solution-Notebook)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Constraints\n",
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"* Is this a binary tree?\n",
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" * Yes\n",
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"* Is the root set to None initially?\n",
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" * Yes\n",
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"* Do we care if the tree is balanced?\n",
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" * No\n",
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"* What do we return for the traversals?\n",
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" * Return a list of the data in the desired order\n",
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"* What type of data can the tree hold?\n",
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" * Assume the tree only takes ints. In a realistic example, we'd use a hash table to convert other types to ints."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Test Cases\n",
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"\n",
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"### Insert \n",
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"\n",
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"* Always start with the root\n",
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"* If value is less than the root, go to the left child\n",
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"* if value is more than the root, go to the right child\n",
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"\n",
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"\n",
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"### Delete\n",
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"\n",
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"* Deleting a node from a binary tree is tricky. Make sure you arrange the tree correctly when deleting a node.\n",
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"* Here are some basic [instructions](http://www.algolist.net/Data_structures/Binary_search_tree/Removal)\n",
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"* If the value to delete isn't on the tree return False\n",
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"\n",
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"### Traverals \n",
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"\n",
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"* In order traversal -left, center, right\n",
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"* Pre order traversal - center, left, right\n",
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"* Post order traversal - left, right, center\n",
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"* Return list for all traverals \n",
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"\n",
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"### Max & Min\n",
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"* Find the max node in the binary search tree\n",
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"* Find the min node in the binary search tree\n",
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"\n",
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"### treeIsEmpty\n",
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"* check if the tree is empty\n",
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"\n",
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"\n",
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"## Algorithm\n",
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"\n",
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"Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/binary_tree_implementation/binary_tree_solution.ipynb). If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Code"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": true
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},
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"outputs": [],
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"source": [
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"class Node (object):\n",
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" def __init__ (self, data=None):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def __str__ (self):\n",
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" #TODO:implement me\n",
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" pass"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": true
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},
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"outputs": [],
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"source": [
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"class BinaryTree (object):\n",
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" def __init__ (self):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def insert (self, newData):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def delete (self, key):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def maxNode (self):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def minNode (self):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def printPostOrder (self):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def printPreOrder (self):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def printInOrder (self):\n",
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" #TODO:implement me\n",
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" pass\n",
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" \n",
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" def treeIsEmpty (self):\n",
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" #TODO: implement me\n",
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" pass\n"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Unit Test"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"**The following unit test is expected to fail until you solve the challenge.**"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 4,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"from nose.tools import assert_equal\n",
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"\n",
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"class TestBinaryTree(object):\n",
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"\n",
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"\tdef test_insert_traversals (self):\n",
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"\t\tmyTree = BinaryTree()\n",
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"\t\tmyTree2 = BinaryTree()\n",
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"\t\tfor num in [50, 30, 70, 10, 40, 60, 80, 7, 25, 38]:\n",
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"\t\t\tmyTree.insert(num)\n",
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"\t\t[myTree2.insert(num) for num in range (1, 100, 10)]\n",
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"\n",
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"\t\tprint(\"Test: insert checking with in order traversal\")\n",
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"\t\tassert_equal(myTree.printInOrder(), [7, 10, 25, 30, 38, 40, 50, 60, 70, 80])\n",
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"\t\tassert_equal(myTree2.printInOrder(), [1, 11, 21, 31, 41, 51, 61, 71, 81, 91])\n",
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"\t\tprint(\"Test: insert checking with post order traversal\")\n",
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"\t\tassert_equal(myTree.printPostOrder(), [7, 25, 10, 38, 40, 30, 60, 80, 70, 50])\n",
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"\t\tassert_equal(myTree2.printPostOrder(), [91, 81, 71, 61, 51, 41, 31, 21, 11, 1])\n",
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"\n",
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"\n",
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"\t\tprint(\"Test: insert checking with pre order traversal\")\n",
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"\t\tassert_equal(myTree.printPreOrder(), [50, 30, 10, 7, 25, 40, 38, 70, 60, 80])\n",
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"\t\tassert_equal(myTree2.printPreOrder(), [1, 11, 21, 31, 41, 51, 61, 71, 81, 91])\n",
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"\n",
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"\n",
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"\t\tprint(\"Success: test_insert_traversals\")\n",
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"\n",
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"\tdef test_max_min_nodes (self):\n",
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"\t\tmyTree = BinaryTree()\n",
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"\t\tmyTree.insert(5)\n",
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"\t\tmyTree.insert(1)\n",
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"\t\tmyTree.insert(21)\n",
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"\n",
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"\t\tprint(\"Test: max node\")\n",
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"\t\tassert_equal(myTree.maxNode(), 21)\n",
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"\t\tmyTree.insert(32)\n",
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"\t\tassert_equal(myTree.maxNode(), 32)\n",
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"\n",
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"\t\tprint(\"Test: min node\")\n",
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"\t\tassert_equal(myTree.minNode(), 1)\n",
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"\n",
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"\t\tprint(\"Test: min node inserting negative number\")\n",
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"\t\tmyTree.insert(-10)\n",
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"\t\tassert_equal(myTree.minNode(), -10)\n",
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"\n",
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"\t\tprint(\"Success: test_max_min_nodes\")\n",
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"\n",
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"\tdef test_delete (self):\n",
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"\t\tmyTree = BinaryTree()\n",
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"\t\tmyTree.insert(5)\n",
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"\n",
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"\t\tprint(\"Test: delete\")\n",
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"\t\tmyTree.delete(5)\n",
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"\t\tassert_equal(myTree.treeIsEmpty(), True)\n",
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"\t\t\n",
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"\t\tprint(\"Test: more complex deletions\")\n",
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"\t\t[myTree.insert(x) for x in range(1, 5)]\n",
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"\t\tmyTree.delete(2)\n",
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"\t\tassert_equal(myTree.root.rightChild.data, 3)\n",
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"\n",
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"\n",
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"\t\tprint(\"Success: test_delete\")\n",
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"\n",
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"def main():\n",
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" testing = TestBinaryTree()\n",
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" testing.test_insert_traversals()\n",
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" testing.test_max_min_nodes()\n",
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" testing.test_delete()\n",
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" \n",
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"if __name__=='__main__':\n",
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" main()\n",
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" "
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Solution NoteBook\n",
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"\n",
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"Review the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/binary_tree_implementation/binary_tree_solution.ipynb) for a discussion on algorithms and code solutions."
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.4.3"
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}
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"nbformat": 4,
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"nbformat_minor": 0
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