From 78dbf4ef9becfc804b98063bccd64eb963e22912 Mon Sep 17 00:00:00 2001 From: Donne Martin Date: Wed, 1 Jul 2015 06:47:09 -0400 Subject: [PATCH] Added quicksort challenge. --- sorting_searching/quick_sort/__init__.py | 0 .../quick_sort/quick_sort_challenge.ipynb | 154 ++++++++++++++++++ .../quick_sort/quick_sort_solution.ipynb | 67 ++++++-- .../quick_sort/test_quick_sort.py | 34 ++++ 4 files changed, 238 insertions(+), 17 deletions(-) create mode 100644 sorting_searching/quick_sort/__init__.py create mode 100644 sorting_searching/quick_sort/quick_sort_challenge.ipynb create mode 100644 sorting_searching/quick_sort/test_quick_sort.py diff --git a/sorting_searching/quick_sort/__init__.py b/sorting_searching/quick_sort/__init__.py new file mode 100644 index 0000000..e69de29 diff --git a/sorting_searching/quick_sort/quick_sort_challenge.ipynb b/sorting_searching/quick_sort/quick_sort_challenge.ipynb new file mode 100644 index 0000000..1c42b7d --- /dev/null +++ b/sorting_searching/quick_sort/quick_sort_challenge.ipynb @@ -0,0 +1,154 @@ +{ + "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 quick sort.\n", + "\n", + "* [Constraints](#Constraints)\n", + "* [Test Cases](#Test-Cases)\n", + "* [Algorithm](#Algorithm)\n", + "* [Code](#Code)\n", + "* [Unit Test](#Unit-Test)\n", + "* [Pythonic-Code](#Pythonic-Code)" + ] + }, + { + "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 (ie not in-place)?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "* Empty input -> []\n", + "* One element -> [element]\n", + "* Two or more elements" + ] + }, + { + "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 quick_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_quick_sort.py\n", + "from nose.tools import assert_equal\n", + "\n", + "\n", + "class TestQuickSort(object):\n", + " def test_quick_sort(self, func):\n", + " print('Empty input')\n", + " data = []\n", + " func(data)\n", + " assert_equal(data, [])\n", + "\n", + " print('One element')\n", + " data = [5]\n", + " func(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 = func(data)\n", + " assert_equal(data, sorted(data))\n", + " \n", + " print('Success: test_quick_sort\\n')\n", + "\n", + "def main():\n", + " test = TestQuickSort()\n", + " test.test_quick_sort(quick_sort)\n", + " try:\n", + " test.test_quick_sort(quick_sort_alt)\n", + " except NameError:\n", + " # Alternate solutions are only defined\n", + " # in the solutions file\n", + " pass\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/quick_sort/quick_sort_solution.ipynb b/sorting_searching/quick_sort/quick_sort_solution.ipynb index 2b598b4..307caea 100644 --- a/sorting_searching/quick_sort/quick_sort_solution.ipynb +++ b/sorting_searching/quick_sort/quick_sort_solution.ipynb @@ -29,7 +29,7 @@ "\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 (ie not in-place)?\n", + "* Is a naiive solution sufficient (ie not in-place)?\n", " * Yes" ] }, @@ -39,8 +39,8 @@ "source": [ "## Test Cases\n", "\n", - "* Empty input\n", - "* One element\n", + "* Empty input -> []\n", + "* One element -> [element]\n", "* Two or more elements" ] }, @@ -89,6 +89,8 @@ " right = []\n", " pivot_index = len(data) / 2\n", " pivot_value = data[pivot_index]\n", + " \n", + " # Build the left and right partitions\n", " for i in xrange(0, len(data)):\n", " if i == pivot_index:\n", " continue\n", @@ -96,6 +98,8 @@ " left.append(data[i])\n", " else:\n", " right.append(data[i])\n", + " \n", + " # Recursively apply quick_sort\n", " left = quick_sort(left)\n", " right = quick_sort(right)\n", " return left + [pivot_value] + right" @@ -145,23 +149,16 @@ "name": "stdout", "output_type": "stream", "text": [ - "Empty input\n", - "One element\n", - "Two or more elements\n", - "Success: test_quick_sort\n", - "\n", - "Empty input\n", - "One element\n", - "Two or more elements\n", - "Success: test_quick_sort\n", - "\n" + "Overwriting test_quick_sort.py\n" ] } ], "source": [ + "%%writefile test_quick_sort.py\n", "from nose.tools import assert_equal\n", "\n", - "class Test(object):\n", + "\n", + "class TestQuickSort(object):\n", " def test_quick_sort(self, func):\n", " print('Empty input')\n", " data = []\n", @@ -180,10 +177,46 @@ " \n", " print('Success: test_quick_sort\\n')\n", "\n", - "if __name__ == '__main__':\n", - " test = Test()\n", + "def main():\n", + " test = TestQuickSort()\n", " test.test_quick_sort(quick_sort)\n", - " test.test_quick_sort(quick_sort_alt)" + " try:\n", + " test.test_quick_sort(quick_sort_alt)\n", + " except NameError:\n", + " # Alternate solutions are only defined\n", + " # in the solutions file\n", + " pass\n", + " \n", + "if __name__ == '__main__':\n", + " main()" + ] + }, + { + "cell_type": "code", + "execution_count": 4, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Empty input\n", + "One element\n", + "Two or more elements\n", + "Success: test_quick_sort\n", + "\n", + "Empty input\n", + "One element\n", + "Two or more elements\n", + "Success: test_quick_sort\n", + "\n" + ] + } + ], + "source": [ + "%run -i test_quick_sort.py" ] } ], diff --git a/sorting_searching/quick_sort/test_quick_sort.py b/sorting_searching/quick_sort/test_quick_sort.py new file mode 100644 index 0000000..ffa1937 --- /dev/null +++ b/sorting_searching/quick_sort/test_quick_sort.py @@ -0,0 +1,34 @@ +from nose.tools import assert_equal + + +class TestQuickSort(object): + def test_quick_sort(self, func): + print('Empty input') + data = [] + func(data) + assert_equal(data, []) + + print('One element') + data = [5] + func(data) + assert_equal(data, [5]) + + print('Two or more elements') + data = [5, 1, 7, 2, 6, -3, 5, 7, -1] + data = func(data) + assert_equal(data, sorted(data)) + + print('Success: test_quick_sort\n') + +def main(): + test = TestQuickSort() + test.test_quick_sort(quick_sort) + try: + test.test_quick_sort(quick_sort_alt) + except NameError: + # Alternate solutions are only defined + # in the solutions file + pass + +if __name__ == '__main__': + main() \ No newline at end of file