diff --git a/arrays_strings/rotation/rotation_challenge.ipynb b/arrays_strings/rotation/rotation_challenge.ipynb new file mode 100644 index 0000000..5fa026b --- /dev/null +++ b/arrays_strings/rotation/rotation_challenge.ipynb @@ -0,0 +1,136 @@ +{ + "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: Determine if a string s1 is a rotation of another string s2, by calling (only once) a function is_substring\n", + "\n", + "* [Constraints and Assumptions](#Constraints-and-Assumptions)\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", + "* Can I assume the string is ASCII?\n", + " * Yes\n", + " * Note: Unicode strings could require special handling depending on your language\n", + "* Can you use additional data structures? \n", + " * Yes\n", + "* Is this case sensitive?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "* Any strings that differ in size -> False\n", + "* None, 'foo' -> False (any None results in False)\n", + "* ' ', 'foo' -> False\n", + "* ' ', ' ' -> True\n", + "* 'foobarbaz', 'barbazfoo' -> True" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Algorithm\n", + "\n", + "Refer to the solution notebook for the algorithm." + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Code" + ] + }, + { + "cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "def is_substring(s1, s2):\n", + " # TODO: Implement me\n", + " pass\n", + "\n", + "def is_rotation(s1, s2):\n", + " # TODO: Implement me\n", + " # Call is_substring only once\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.*\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_rotation.py" + ] + } + ], + "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/arrays_strings/rotation/rotation_solution.ipynb b/arrays_strings/rotation/rotation_solution.ipynb index c35405e..8d0ca9b 100644 --- a/arrays_strings/rotation/rotation_solution.ipynb +++ b/arrays_strings/rotation/rotation_solution.ipynb @@ -11,7 +11,7 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "## Problem: Determine if a string s1 is a rotation of another string s2. Also write a function is_substring which you can only call once to determine whether a rotation occurs\n", + "## Problem: Determine if a string s1 is a rotation of another string s2, by calling (only once) a function is_substring\n", "\n", "* [Constraints and Assumptions](#Constraints-and-Assumptions)\n", "* [Test Cases](#Test-Cases)\n", @@ -43,8 +43,8 @@ "source": [ "## Test Cases\n", "\n", - "* Any strings that differ in size results in False\n", - "* NULL, 'foo' -> False (any NULL results in False)\n", + "* Any strings that differ in size -> False\n", + "* None, 'foo' -> False (any None results in False)\n", "* ' ', 'foo' -> False\n", "* ' ', ' ' -> True\n", "* 'foobarbaz', 'barbazfoo' -> True" @@ -84,7 +84,7 @@ }, "outputs": [], "source": [ - "def is_substring(s1, s2):\n", + "def is_substring(s1, s2): \n", " return s1 in s2\n", "\n", "def is_rotation(s1, s2):\n", @@ -121,25 +121,50 @@ "name": "stdout", "output_type": "stream", "text": [ - "Success: test_is_rotation\n" + "Overwriting test_rotation.py\n" ] } ], "source": [ + "%%writefile test_rotation.py\n", "from nose.tools import assert_equal\n", "\n", - "class Test(object):\n", - " def test_is_rotation(self, func):\n", - " assert_equal(func('o', 'oo'), False)\n", - " assert_equal(func(None, 'foo'), False)\n", - " assert_equal(func('', 'foo'), False)\n", - " assert_equal(func('', ''), True)\n", - " assert_equal(func('foobarbaz', 'barbazfoo'), True)\n", - " print('Success: test_is_rotation')\n", + "\n", + "class TestRotation(object):\n", + " \n", + " def test_rotation(self):\n", + " assert_equal(is_rotation('o', 'oo'), False)\n", + " assert_equal(is_rotation(None, 'foo'), False)\n", + " assert_equal(is_rotation('', 'foo'), False)\n", + " assert_equal(is_rotation('', ''), True)\n", + " assert_equal(is_rotation('foobarbaz', 'barbazfoo'), True)\n", + " print('Success: test_rotation')\n", + "\n", + "def main():\n", + " test = TestRotation()\n", + " test.test_rotation()\n", "\n", "if __name__ == '__main__':\n", - " test = Test()\n", - " test.test_is_rotation(is_rotation)" + " main()" + ] + }, + { + "cell_type": "code", + "execution_count": 7, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Success: test_rotation\n" + ] + } + ], + "source": [ + "%run -i test_rotation.py" ] } ], diff --git a/arrays_strings/rotation/test_rotation.py b/arrays_strings/rotation/test_rotation.py new file mode 100644 index 0000000..9daf22f --- /dev/null +++ b/arrays_strings/rotation/test_rotation.py @@ -0,0 +1,19 @@ +from nose.tools import assert_equal + + +class TestRotation(object): + + def test_rotation(self): + assert_equal(is_rotation('o', 'oo'), False) + assert_equal(is_rotation(None, 'foo'), False) + assert_equal(is_rotation('', 'foo'), False) + assert_equal(is_rotation('', ''), True) + assert_equal(is_rotation('foobarbaz', 'barbazfoo'), True) + print('Success: test_rotation') + +def main(): + test = TestRotation() + test.test_rotation() + +if __name__ == '__main__': + main() \ No newline at end of file