mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
synced 2024-03-22 13:11:13 +08:00
Added partition challenge.
This commit is contained in:
Donne Martin
parent
d79ee29ec8
commit
c16f25e5f3
0
linked_lists/partition/__init__.py
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0
linked_lists/partition/__init__.py
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211
linked_lists/partition/partition_challenge.ipynb
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211
linked_lists/partition/partition_challenge.ipynb
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{
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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 [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/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: Partition a linked list around a value x, such that all nodes less than x come before all nodes greater than or equal to x.\n",
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"\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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"\n",
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"*Problem statements are sometimes ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
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"\n",
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"* Can we create additional data structures?\n",
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" * Yes\n",
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"* Do you expect the function to return a new list?\n",
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" * Yes\n",
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"* Can we assume the input x is valid?\n",
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" * Yes\n",
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"* Can we assume we already have a linked list class that can be used for this problem?\n",
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" * Yes"
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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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"* Empty list -> []\n",
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"* One element list -> [element]\n",
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"* Left linked list is empty\n",
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"* Right linked list is empty\n",
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"* General case\n",
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" * Partition = 10\n",
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" * Input: 4, 3, 7, 8, 10, 1, 10, 12\n",
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" * Output: 4, 3, 7, 8, 1, 10, 10, 12"
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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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"## Algorithm\n",
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"\n",
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"Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/coding-challenges/blob/master/linked_lists/partition/partition_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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"%run ../linked_list/linked_list.py\n",
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"%load ../linked_list/linked_list.py"
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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": false
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},
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"outputs": [],
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"source": [
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"class MyLinkedList(LinkedList):\n",
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" \n",
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" def partition(self, data):\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": "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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"\n",
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"\n",
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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": null,
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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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"# %load test_partition.py\n",
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"from nose.tools import assert_equal\n",
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"\n",
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"\n",
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"class TestPartition(object):\n",
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" \n",
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" def test_partition(self):\n",
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" print('Test: Empty list')\n",
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" linked_list = MyLinkedList(None)\n",
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" linked_list.partition(10)\n",
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" assert_equal(linked_list.get_all_data(), [])\n",
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"\n",
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" print('Test: One element list, left list empty')\n",
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" linked_list = MyLinkedList(Node(5))\n",
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" linked_list.partition(0)\n",
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" assert_equal(linked_list.get_all_data(), [5])\n",
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"\n",
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" print('Test: Right list is empty')\n",
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" linked_list = MyLinkedList(Node(5))\n",
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" linked_list.partition(10)\n",
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" assert_equal(linked_list.get_all_data(), [5])\n",
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"\n",
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" print('Test: General case')\n",
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" # Partition = 10\n",
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" # Input: 4, 3, 7, 8, 10, 1, 10, 12\n",
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" # Output: 4, 3, 7, 8, 1, 10, 10, 12\n",
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" linked_list = MyLinkedList(Node(12))\n",
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" linked_list.insert_to_front(10)\n",
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" linked_list.insert_to_front(1)\n",
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" linked_list.insert_to_front(10)\n",
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" linked_list.insert_to_front(8)\n",
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" linked_list.insert_to_front(7)\n",
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" linked_list.insert_to_front(3)\n",
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" linked_list.insert_to_front(4)\n",
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" partitioned_list = linked_list.partition(10)\n",
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" assert_equal(partitioned_list.get_all_data(), \n",
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" [4, 3, 7, 8, 1, 10, 10, 12])\n",
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" \n",
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" print('Success: test_partition')\n",
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"\n",
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"def main():\n",
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" test = TestPartition()\n",
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" test.test_partition()\n",
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" \n",
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"if __name__ == '__main__':\n",
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" main()"
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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/coding-challenges/blob/master/linked_lists/partition/partition_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 2",
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"language": "python",
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"name": "python2"
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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": 2
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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": "ipython2",
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"version": "2.7.10"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 0
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}
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@ -4,7 +4,14 @@
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"cell_type": "markdown",
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"cell_type": "markdown",
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"metadata": {},
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"metadata": {},
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||||||
"source": [
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"source": [
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"<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>"
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"<small><i>This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/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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"# Solution Notebook"
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]
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]
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},
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},
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{
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{
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@ -26,7 +33,7 @@
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"source": [
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"source": [
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"## Constraints\n",
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"## Constraints\n",
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"\n",
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"\n",
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"*Problem statements are often intentionally ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
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"*Problem statements are sometimes ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
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"\n",
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"\n",
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"* Can we create additional data structures?\n",
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"* Can we create additional data structures?\n",
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" * Yes\n",
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" * Yes\n",
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@ -44,8 +51,8 @@
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"source": [
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"source": [
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"## Test Cases\n",
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"## Test Cases\n",
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"\n",
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"\n",
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"* Empty list\n",
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"* Empty list -> []\n",
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"* One element list\n",
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"* One element list -> [element]\n",
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"* Left linked list is empty\n",
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"* Left linked list is empty\n",
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"* Right linked list is empty\n",
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"* Right linked list is empty\n",
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"* General case\n",
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"* General case\n",
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@ -86,7 +93,7 @@
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},
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},
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"outputs": [],
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"outputs": [],
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"source": [
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"source": [
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"%run linked_list.py"
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"%run ../linked_list/linked_list.py"
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]
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]
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},
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},
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{
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@ -98,6 +105,7 @@
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"outputs": [],
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"outputs": [],
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"source": [
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"source": [
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"class MyLinkedList(LinkedList):\n",
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"class MyLinkedList(LinkedList):\n",
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" \n",
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" def partition(self, data):\n",
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" def partition(self, data):\n",
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" if self.head is None:\n",
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" if self.head is None:\n",
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" return\n",
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" return\n",
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"## Unit Test"
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"## Unit Test"
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]
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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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"*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.*"
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]
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},
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{
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{
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"cell_type": "code",
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"cell_type": "code",
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"execution_count": 3,
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"execution_count": 3,
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"name": "stdout",
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"name": "stdout",
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"output_type": "stream",
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"output_type": "stream",
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"text": [
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"text": [
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"Test: Empty list\n",
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"Overwriting test_partition.py\n"
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"Test: One element list, left list empty\n",
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"Test: Right list is empty\n",
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"Test: General case\n",
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"Success: test_partition\n"
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]
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]
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}
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}
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],
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],
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"source": [
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"source": [
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"%%writefile test_partition.py\n",
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"from nose.tools import assert_equal\n",
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"from nose.tools import assert_equal\n",
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"\n",
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"\n",
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"class Test(object):\n",
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"\n",
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"class TestPartition(object):\n",
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" \n",
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" def test_partition(self):\n",
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" def test_partition(self):\n",
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" print('Test: Empty list')\n",
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" print('Test: Empty list')\n",
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" linked_list = MyLinkedList(None)\n",
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" linked_list = MyLinkedList(None)\n",
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" \n",
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" \n",
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" print('Success: test_partition')\n",
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" print('Success: test_partition')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestPartition()\n",
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" test.test_partition()\n",
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" \n",
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"if __name__ == '__main__':\n",
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"if __name__ == '__main__':\n",
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" test = Test()\n",
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" main()"
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" test.test_partition()"
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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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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"Test: Empty list\n",
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"Test: One element list, left list empty\n",
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"Test: Right list is empty\n",
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"Test: General case\n",
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"Success: test_partition\n"
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]
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}
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],
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"source": [
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"run -i test_partition.py"
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]
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]
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}
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}
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],
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],
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45
linked_lists/partition/test_partition.py
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45
linked_lists/partition/test_partition.py
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from nose.tools import assert_equal
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class TestPartition(object):
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def test_partition(self):
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print('Test: Empty list')
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linked_list = MyLinkedList(None)
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linked_list.partition(10)
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assert_equal(linked_list.get_all_data(), [])
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print('Test: One element list, left list empty')
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linked_list = MyLinkedList(Node(5))
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linked_list.partition(0)
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assert_equal(linked_list.get_all_data(), [5])
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print('Test: Right list is empty')
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linked_list = MyLinkedList(Node(5))
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linked_list.partition(10)
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assert_equal(linked_list.get_all_data(), [5])
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print('Test: General case')
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# Partition = 10
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# Input: 4, 3, 7, 8, 10, 1, 10, 12
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# Output: 4, 3, 7, 8, 1, 10, 10, 12
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linked_list = MyLinkedList(Node(12))
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linked_list.insert_to_front(10)
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linked_list.insert_to_front(1)
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||||||
|
linked_list.insert_to_front(10)
|
||||||
|
linked_list.insert_to_front(8)
|
||||||
|
linked_list.insert_to_front(7)
|
||||||
|
linked_list.insert_to_front(3)
|
||||||
|
linked_list.insert_to_front(4)
|
||||||
|
partitioned_list = linked_list.partition(10)
|
||||||
|
assert_equal(partitioned_list.get_all_data(),
|
||||||
|
[4, 3, 7, 8, 1, 10, 10, 12])
|
||||||
|
|
||||||
|
print('Success: test_partition')
|
||||||
|
|
||||||
|
def main():
|
||||||
|
test = TestPartition()
|
||||||
|
test.test_partition()
|
||||||
|
|
||||||
|
if __name__ == '__main__':
|
||||||
|
main()
|
||||||
Loading…
Reference in New Issue
Block a user