mirror of
https://github.com/donnemartin/interactive-coding-challenges
synced 2026-01-07 09:58:03 +00:00
Added palindrome challenge.
This commit is contained in:
Donne Martin
184
linked_lists/palindrome/palindrome_challenge.ipynb
Normal file
184
linked_lists/palindrome/palindrome_challenge.ipynb
Normal file
@@ -0,0 +1,184 @@
|
||||
{
|
||||
"cells": [
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"<small><i>This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://bit.ly/code-notes).</i></small>"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Problem: Determine if a linked list is a palindrome.\n",
|
||||
"\n",
|
||||
"* [Constraints](#Constraints)\n",
|
||||
"* [Test Cases](#Test-Cases)\n",
|
||||
"* [Algorithm](#Algorithm)\n",
|
||||
"* [Code](#Code)\n",
|
||||
"* [Unit Test](#Unit-Test)"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Constraints\n",
|
||||
"\n",
|
||||
"*Problem statements are often intentionally ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
|
||||
"\n",
|
||||
"* Is a single character or number a palindrome?\n",
|
||||
" * No\n",
|
||||
"* Can we assume we already have a linked list class that can be used for this problem?\n",
|
||||
" * Yes"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Test Cases\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"* Empty list -> False\n",
|
||||
"* Single element list -> False\n",
|
||||
"* Two or more element list, not a palindrome -> False\n",
|
||||
"* General case: Palindrome with even length -> True\n",
|
||||
"* General case: Palindrome with odd length -> True"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Algorithm\n",
|
||||
"\n",
|
||||
"Refer to the solution notebook. 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": {
|
||||
"collapsed": false
|
||||
},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"%run ../linked_list/linked_list.py"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {
|
||||
"collapsed": false
|
||||
},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"class MyLinkedList(LinkedList):\n",
|
||||
" \n",
|
||||
" def is_palindrome(self):\n",
|
||||
" # TODO: Implement me\n",
|
||||
" pass"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Unit Test"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"*It is important to identify and run through general and edge cases from the [Test Cases](#Test-Cases) section by hand. You generally will not be asked to write a unit test like what is shown below.*"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {
|
||||
"collapsed": false
|
||||
},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"# %load test_palindrome.py\n",
|
||||
"from nose.tools import assert_equal\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class TestPalindrome(object):\n",
|
||||
" \n",
|
||||
" def test_palindrome(self):\n",
|
||||
" print('Test: Empty list')\n",
|
||||
" linked_list = MyLinkedList()\n",
|
||||
" assert_equal(linked_list.is_palindrome(), False)\n",
|
||||
"\n",
|
||||
" print('Test: Single element list')\n",
|
||||
" head = Node(1)\n",
|
||||
" linked_list = MyLinkedList(head)\n",
|
||||
" assert_equal(linked_list.is_palindrome(), False)\n",
|
||||
"\n",
|
||||
" print('Test: Two element list, not a palindrome')\n",
|
||||
" linked_list.append(2)\n",
|
||||
" assert_equal(linked_list.is_palindrome(), False)\n",
|
||||
"\n",
|
||||
" print('Test: General case: Palindrome with even length')\n",
|
||||
" head = Node('a')\n",
|
||||
" linked_list = MyLinkedList(head)\n",
|
||||
" linked_list.append('b')\n",
|
||||
" linked_list.append('b')\n",
|
||||
" linked_list.append('a')\n",
|
||||
" assert_equal(linked_list.is_palindrome(), True)\n",
|
||||
"\n",
|
||||
" print('Test: General case: Palindrome with odd length')\n",
|
||||
" head = Node(1)\n",
|
||||
" linked_list = MyLinkedList(head)\n",
|
||||
" linked_list.append(2)\n",
|
||||
" linked_list.append(3)\n",
|
||||
" linked_list.append(2)\n",
|
||||
" linked_list.append(1)\n",
|
||||
" assert_equal(linked_list.is_palindrome(), True)\n",
|
||||
" \n",
|
||||
" print('Success: test_palindrome')\n",
|
||||
"\n",
|
||||
"def main():\n",
|
||||
" test = TestPalindrome()\n",
|
||||
" test.test_palindrome()\n",
|
||||
"\n",
|
||||
"if __name__ == '__main__':\n",
|
||||
" main()"
|
||||
]
|
||||
}
|
||||
],
|
||||
"metadata": {
|
||||
"kernelspec": {
|
||||
"display_name": "Python 2",
|
||||
"language": "python",
|
||||
"name": "python2"
|
||||
},
|
||||
"language_info": {
|
||||
"codemirror_mode": {
|
||||
"name": "ipython",
|
||||
"version": 2
|
||||
},
|
||||
"file_extension": ".py",
|
||||
"mimetype": "text/x-python",
|
||||
"name": "python",
|
||||
"nbconvert_exporter": "python",
|
||||
"pygments_lexer": "ipython2",
|
||||
"version": "2.7.10"
|
||||
}
|
||||
},
|
||||
"nbformat": 4,
|
||||
"nbformat_minor": 0
|
||||
}
|
||||
Reference in New Issue
Block a user