Files
interactive-coding-challenges/linked_lists/linked_list/linked_list_challenge.ipynb
2020-07-06 21:09:04 -04:00

329 lines
9.6 KiB
Python

{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Challenge Notebook"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Problem: Implement a linked list with insert, append, find, delete, length, and print methods.\n",
"\n",
"* [Constraints](#Constraints)\n",
"* [Test Cases](#Test-Cases)\n",
"* [Algorithm](#Algorithm)\n",
"* [Code](#Code)\n",
"* [Unit Test](#Unit-Test)\n",
"* [Solution Notebook](#Solution-Notebook)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Constraints\n",
"\n",
"* Can we assume this is a non-circular, singly linked list?\n",
" * Yes\n",
"* Do we keep track of the tail or just the head?\n",
" * Just the head\n",
"* Can we insert None values?\n",
" * No"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Test Cases\n",
"\n",
"### Insert to Front\n",
"\n",
"* Insert a None\n",
"* Insert in an empty list\n",
"* Insert in a list with one element or more elements\n",
"\n",
"### Append\n",
"\n",
"* Append a None\n",
"* Append in an empty list\n",
"* Insert in a list with one element or more elements\n",
"\n",
"### Find\n",
"\n",
"* Find a None\n",
"* Find in an empty list\n",
"* Find in a list with one element or more matching elements\n",
"* Find in a list with no matches\n",
"\n",
"### Delete\n",
"\n",
"* Delete a None\n",
"* Delete in an empty list\n",
"* Delete in a list with one element or more matching elements\n",
"* Delete in a list with no matches\n",
"\n",
"### Length\n",
"\n",
"* Length of zero or more elements\n",
"\n",
"### Print\n",
"\n",
"* Print an empty list\n",
"* Print a list with one or more elements"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Algorithm\n",
"\n",
"Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/linked_lists/linked_list/linked_list_solution.ipynb). If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Code"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"class Node(object):\n",
"\n",
" def __init__(self, data, next_node=None):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def __str__(self):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
"\n",
"class LinkedList(object):\n",
"\n",
" def __init__(self, head=None):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def __len__(self):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def insert_to_front(self, data):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def append(self, data):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def find(self, data):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def delete(self, data):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def print_list(self):\n",
" pass\n",
" # TODO: Implement me\n",
"\n",
" def get_all_data(self):\n",
" pass\n",
" # TODO: Implement me"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Unit Test"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"\n",
"\n",
"**The following unit test is expected to fail until you solve the challenge.**"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"# %load test_linked_list.py\n",
"import unittest\n",
"\n",
"\n",
"class TestLinkedList(unittest.TestCase):\n",
"\n",
" def test_insert_to_front(self):\n",
" print('Test: insert_to_front on an empty list')\n",
" linked_list = LinkedList(None)\n",
" linked_list.insert_to_front(10)\n",
" self.assertEqual(linked_list.get_all_data(), [10])\n",
"\n",
" print('Test: insert_to_front on a None')\n",
" linked_list.insert_to_front(None)\n",
" self.assertEqual(linked_list.get_all_data(), [10])\n",
"\n",
" print('Test: insert_to_front general case')\n",
" linked_list.insert_to_front('a')\n",
" linked_list.insert_to_front('bc')\n",
" self.assertEqual(linked_list.get_all_data(), ['bc', 'a', 10])\n",
"\n",
" print('Success: test_insert_to_front\\n')\n",
"\n",
" def test_append(self):\n",
" print('Test: append on an empty list')\n",
" linked_list = LinkedList(None)\n",
" linked_list.append(10)\n",
" self.assertEqual(linked_list.get_all_data(), [10])\n",
"\n",
" print('Test: append a None')\n",
" linked_list.append(None)\n",
" self.assertEqual(linked_list.get_all_data(), [10])\n",
"\n",
" print('Test: append general case')\n",
" linked_list.append('a')\n",
" linked_list.append('bc')\n",
" self.assertEqual(linked_list.get_all_data(), [10, 'a', 'bc'])\n",
"\n",
" print('Success: test_append\\n')\n",
"\n",
" def test_find(self):\n",
" print('Test: find on an empty list')\n",
" linked_list = LinkedList(None)\n",
" node = linked_list.find('a')\n",
" self.assertEqual(node, None)\n",
"\n",
" print('Test: find a None')\n",
" head = Node(10)\n",
" linked_list = LinkedList(head)\n",
" node = linked_list.find(None)\n",
" self.assertEqual(node, None)\n",
"\n",
" print('Test: find general case with matches')\n",
" head = Node(10)\n",
" linked_list = LinkedList(head)\n",
" linked_list.insert_to_front('a')\n",
" linked_list.insert_to_front('bc')\n",
" node = linked_list.find('a')\n",
" self.assertEqual(str(node), 'a')\n",
"\n",
" print('Test: find general case with no matches')\n",
" node = linked_list.find('aaa')\n",
" self.assertEqual(node, None)\n",
"\n",
" print('Success: test_find\\n')\n",
"\n",
" def test_delete(self):\n",
" print('Test: delete on an empty list')\n",
" linked_list = LinkedList(None)\n",
" linked_list.delete('a')\n",
" self.assertEqual(linked_list.get_all_data(), [])\n",
"\n",
" print('Test: delete a None')\n",
" head = Node(10)\n",
" linked_list = LinkedList(head)\n",
" linked_list.delete(None)\n",
" self.assertEqual(linked_list.get_all_data(), [10])\n",
"\n",
" print('Test: delete general case with matches')\n",
" head = Node(10)\n",
" linked_list = LinkedList(head)\n",
" linked_list.insert_to_front('a')\n",
" linked_list.insert_to_front('bc')\n",
" linked_list.delete('a')\n",
" self.assertEqual(linked_list.get_all_data(), ['bc', 10])\n",
"\n",
" print('Test: delete general case with no matches')\n",
" linked_list.delete('aa')\n",
" self.assertEqual(linked_list.get_all_data(), ['bc', 10])\n",
"\n",
" print('Success: test_delete\\n')\n",
"\n",
" def test_len(self):\n",
" print('Test: len on an empty list')\n",
" linked_list = LinkedList(None)\n",
" self.assertEqual(len(linked_list), 0)\n",
"\n",
" print('Test: len general case')\n",
" head = Node(10)\n",
" linked_list = LinkedList(head)\n",
" linked_list.insert_to_front('a')\n",
" linked_list.insert_to_front('bc')\n",
" self.assertEqual(len(linked_list), 3)\n",
"\n",
" print('Success: test_len\\n')\n",
"\n",
"\n",
"def main():\n",
" test = TestLinkedList()\n",
" test.test_insert_to_front()\n",
" test.test_append()\n",
" test.test_find()\n",
" test.test_delete()\n",
" test.test_len()\n",
"\n",
"\n",
"if __name__ == '__main__':\n",
" main()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Solution Notebook\n",
"\n",
"Review the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/linked_lists/linked_list/linked_list_solution.ipynb) for a discussion on algorithms and code solutions."
]
}
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