From 8ac0bd3f69fae9d1338f296b9de6f17a5b7a2b7d Mon Sep 17 00:00:00 2001 From: Donne Martin Date: Fri, 3 Jul 2015 19:57:24 -0400 Subject: [PATCH] Added unique chars challenge. --- .../unique_chars/test_unique_chars.py | 24 +++ .../unique_chars/unique_chars_challenge.ipynb | 183 ++++++++++++++++++ .../unique_chars/unique_chars_solution.ipynb | 74 +++++-- 3 files changed, 260 insertions(+), 21 deletions(-) create mode 100644 arrays_strings/unique_chars/test_unique_chars.py create mode 100644 arrays_strings/unique_chars/unique_chars_challenge.ipynb diff --git a/arrays_strings/unique_chars/test_unique_chars.py b/arrays_strings/unique_chars/test_unique_chars.py new file mode 100644 index 0000000..50ff05c --- /dev/null +++ b/arrays_strings/unique_chars/test_unique_chars.py @@ -0,0 +1,24 @@ +from nose.tools import assert_equal + + +class TestUniqueChars(object): + + def test_unique_chars(self, func): + assert_equal(func(''), True) + assert_equal(func('foo'), False) + assert_equal(func('bar'), True) + print('Success: test_unique_chars') + +def main(): + test = TestUniqueChars() + test.test_unique_chars(unique_chars) + try: + test.test_unique_chars(unique_chars_hash) + test.test_unique_chars(unique_chars_inplace) + except NameError: + # Alternate solutions are only defined + # in the solutions file + pass + +if __name__ == '__main__': + main() \ No newline at end of file diff --git a/arrays_strings/unique_chars/unique_chars_challenge.ipynb b/arrays_strings/unique_chars/unique_chars_challenge.ipynb new file mode 100644 index 0000000..8afd212 --- /dev/null +++ b/arrays_strings/unique_chars/unique_chars_challenge.ipynb @@ -0,0 +1,183 @@ +{ + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/coding-challenges)." + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Challenge Notebook" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Problem: Implement an algorithm to determine if a string has all unique characters\n", + "\n", + "* [Constraints](#Constraints)\n", + "* [Test Cases](#Test-Cases)\n", + "* [Algorithm](#Algorithm)\n", + "* [Code](#Code)\n", + "* [Unit Test](#Unit-Test)\n", + "* [Solution Notebook](#Solution-Notebook)" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Constraints\n", + "\n", + "*Problem statements are sometimes ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n", + "\n", + "* Can you assume the string is ASCII?\n", + " * Yes\n", + " * Note: Unicode strings could require special handling depending on your language\n", + "* Can we assume this is case sensitive?\n", + " * Yes\n", + "* Can you use additional data structures?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "*It is important to identify and run through general and edge cases by hand.*\n", + "\n", + "* '' -> True\n", + "* 'foo' -> False\n", + "* 'bar' -> 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": 3, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "def unique_chars(string):\n", + " chars_set = set()\n", + " for char in string:\n", + " if char in chars_set:\n", + " return False\n", + " else:\n", + " chars_set.add(char)\n", + " return True" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Unit Test" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "**The following unit test is expected to fail until you solve the challenge.**" + ] + }, + { + "cell_type": "code", + "execution_count": 4, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Success: test_unique_chars\n" + ] + } + ], + "source": [ + "# %load test_unique_chars.py\n", + "from nose.tools import assert_equal\n", + "\n", + "\n", + "class TestUniqueChars(object):\n", + "\n", + " def test_unique_chars(self, func):\n", + " assert_equal(func(''), True)\n", + " assert_equal(func('foo'), False)\n", + " assert_equal(func('bar'), True)\n", + " print('Success: test_unique_chars')\n", + "\n", + "def main():\n", + " test = TestUniqueChars()\n", + " test.test_unique_chars(unique_chars)\n", + " try:\n", + " test.test_unique_chars(unique_chars_hash)\n", + " test.test_unique_chars(unique_chars_inplace)\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": "markdown", + "metadata": {}, + "source": [ + "## Solution Notebook\n", + "\n", + "Review the [solution notebook](#) for a discussion on algorithms and code solutions." + ] + } + ], + "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/unique_chars/unique_chars_solution.ipynb b/arrays_strings/unique_chars/unique_chars_solution.ipynb index 5ec3108..92f9a68 100644 --- a/arrays_strings/unique_chars/unique_chars_solution.ipynb +++ b/arrays_strings/unique_chars/unique_chars_solution.ipynb @@ -4,7 +4,14 @@ "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)." + "This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/coding-challenges)." + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Solution Notebook" ] }, { @@ -30,11 +37,13 @@ "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", + "*Problem statements are sometimes 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", + "* Can you assume the string is ASCII?\n", " * Yes\n", " * Note: Unicode strings could require special handling depending on your language\n", + "* Can we assume this is case sensitive?\n", + " * Yes\n", "* Can you use additional data structures? \n", " * Yes" ] @@ -185,15 +194,51 @@ ] }, { - "cell_type": "markdown", - "metadata": {}, + "cell_type": "code", + "execution_count": 4, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Overwriting test_unique_chars.py\n" + ] + } + ], "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.*" + "%%writefile test_unique_chars.py\n", + "from nose.tools import assert_equal\n", + "\n", + "\n", + "class TestUniqueChars(object):\n", + "\n", + " def test_unique_chars(self, func):\n", + " assert_equal(func(''), True)\n", + " assert_equal(func('foo'), False)\n", + " assert_equal(func('bar'), True)\n", + " print('Success: test_unique_chars')\n", + "\n", + "def main():\n", + " test = TestUniqueChars()\n", + " test.test_unique_chars(unique_chars)\n", + " try:\n", + " test.test_unique_chars(unique_chars_hash)\n", + " test.test_unique_chars(unique_chars_inplace)\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, + "execution_count": 5, "metadata": { "collapsed": false }, @@ -209,20 +254,7 @@ } ], "source": [ - "from nose.tools import assert_equal\n", - "\n", - "class Test(object):\n", - " def test_unique_chars(self, func):\n", - " assert_equal(func(''), True)\n", - " assert_equal(func('foo'), False)\n", - " assert_equal(func('bar'), True)\n", - " print('Success: test_unique_chars')\n", - "\n", - "if __name__ == '__main__':\n", - " test = Test()\n", - " test.test_unique_chars(unique_chars)\n", - " test.test_unique_chars(unique_chars_hash)\n", - " test.test_unique_chars(unique_chars_inplace)" + "%run -i test_unique_chars.py" ] } ],