From 5c2f839ccf4ea8796016dc5c50727290b94b261d Mon Sep 17 00:00:00 2001 From: Donne Martin Date: Wed, 1 Jul 2015 06:46:38 -0400 Subject: [PATCH] Added merge sort challenge. --- sorting_searching/merge_sort/__init__.py | 0 .../merge_sort/merge_sort_challenge.ipynb | 148 ++++++++++++++++++ .../merge_sort/merge_sort_solution.ipynb | 46 ++++-- .../merge_sort/test_merge_sort.py | 28 ++++ 4 files changed, 212 insertions(+), 10 deletions(-) create mode 100644 sorting_searching/merge_sort/__init__.py create mode 100644 sorting_searching/merge_sort/merge_sort_challenge.ipynb create mode 100644 sorting_searching/merge_sort/test_merge_sort.py diff --git a/sorting_searching/merge_sort/__init__.py b/sorting_searching/merge_sort/__init__.py new file mode 100644 index 0000000..e69de29 diff --git a/sorting_searching/merge_sort/merge_sort_challenge.ipynb b/sorting_searching/merge_sort/merge_sort_challenge.ipynb new file mode 100644 index 0000000..f22a1b7 --- /dev/null +++ b/sorting_searching/merge_sort/merge_sort_challenge.ipynb @@ -0,0 +1,148 @@ +{ + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://bit.ly/code-notes)." + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Problem: Implement merge sort.\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 naiive solution sufficient?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "* Empty input -> []\n", + "* One element -> [element]\n", + "* Two or more elements\n", + "* Left and right subarrays of different lengths" + ] + }, + { + "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": [ + "def merge_sort(data):\n", + " # TODO: Implement me\n", + " pass" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Unit Test\n", + "\n", + "*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.*\n", + "\n", + "**The following unit test is expected to fail until you solve the challenge.**" + ] + }, + { + "cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "# %load test_merge_sort.py\n", + "from nose.tools import assert_equal\n", + "\n", + "\n", + "class TestMergeSort(object):\n", + " def test_merge_sort(self):\n", + " print('Empty input')\n", + " data = []\n", + " merge_sort(data)\n", + " assert_equal(data, [])\n", + "\n", + " print('One element')\n", + " data = [5]\n", + " merge_sort(data)\n", + " assert_equal(data, [5])\n", + "\n", + " print('Two or more elements')\n", + " data = [5, 1, 7, 2, 6, -3, 5, 7, -1]\n", + " data = merge_sort(data)\n", + " assert_equal(data, sorted(data))\n", + " \n", + " print('Success: test_merge_sort')\n", + "\n", + "def main():\n", + " test = TestMergeSort()\n", + " test.test_merge_sort()\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 +} diff --git a/sorting_searching/merge_sort/merge_sort_solution.ipynb b/sorting_searching/merge_sort/merge_sort_solution.ipynb index 6672786..0ac730b 100644 --- a/sorting_searching/merge_sort/merge_sort_solution.ipynb +++ b/sorting_searching/merge_sort/merge_sort_solution.ipynb @@ -28,7 +28,7 @@ "\n", "*Problem statements are often intentionally ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n", "\n", - "* Are you looking for a naiive solution?\n", + "* Is a naiive solution sufficient?\n", " * Yes" ] }, @@ -38,8 +38,8 @@ "source": [ "## Test Cases\n", "\n", - "* Empty input\n", - "* One element\n", + "* Empty input -> []\n", + "* One element -> [element]\n", "* Two or more elements\n", "* Left and right subarrays of different lengths" ] @@ -92,6 +92,8 @@ " else:\n", " result.append(right[r])\n", " r += 1\n", + " \n", + " # Copy remaining elements\n", " while l < len(left):\n", " result.append(left[l])\n", " l += 1\n", @@ -131,17 +133,16 @@ "name": "stdout", "output_type": "stream", "text": [ - "Empty input\n", - "One element\n", - "Two or more elements\n", - "Success: test_merge_sort\n" + "Overwriting test_merge_sort.py\n" ] } ], "source": [ + "%%writefile test_merge_sort.py\n", "from nose.tools import assert_equal\n", "\n", - "class Test(object):\n", + "\n", + "class TestMergeSort(object):\n", " def test_merge_sort(self):\n", " print('Empty input')\n", " data = []\n", @@ -160,9 +161,34 @@ " \n", " print('Success: test_merge_sort')\n", "\n", + "def main():\n", + " test = TestMergeSort()\n", + " test.test_merge_sort()\n", + "\n", "if __name__ == '__main__':\n", - " test = Test()\n", - " test.test_merge_sort()" + " main()" + ] + }, + { + "cell_type": "code", + "execution_count": 3, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Empty input\n", + "One element\n", + "Two or more elements\n", + "Success: test_merge_sort\n" + ] + } + ], + "source": [ + "%run -i test_merge_sort.py" ] } ], diff --git a/sorting_searching/merge_sort/test_merge_sort.py b/sorting_searching/merge_sort/test_merge_sort.py new file mode 100644 index 0000000..536c9c4 --- /dev/null +++ b/sorting_searching/merge_sort/test_merge_sort.py @@ -0,0 +1,28 @@ +from nose.tools import assert_equal + + +class TestMergeSort(object): + def test_merge_sort(self): + print('Empty input') + data = [] + merge_sort(data) + assert_equal(data, []) + + print('One element') + data = [5] + merge_sort(data) + assert_equal(data, [5]) + + print('Two or more elements') + data = [5, 1, 7, 2, 6, -3, 5, 7, -1] + data = merge_sort(data) + assert_equal(data, sorted(data)) + + print('Success: test_merge_sort') + +def main(): + test = TestMergeSort() + test.test_merge_sort() + +if __name__ == '__main__': + main() \ No newline at end of file