diff --git a/sorting_searching/anagrams/__init__.py b/sorting_searching/anagrams/__init__.py new file mode 100644 index 0000000..e69de29 diff --git a/sorting_searching/anagrams/anagrams_challenge.ipynb b/sorting_searching/anagrams/anagrams_challenge.ipynb new file mode 100644 index 0000000..afdb9e7 --- /dev/null +++ b/sorting_searching/anagrams/anagrams_challenge.ipynb @@ -0,0 +1,170 @@ +{ + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)." + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Challenge Notebook" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Problem: Sort an array of strings so all anagrams are next to each other.\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", + "* Are there any other sorting requirements other than the grouping of anagrams?\n", + " * No\n", + "* Can we assume the inputs are valid?\n", + " * No\n", + "* Can we assume this fits memory?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "* None -> Exception\n", + "* [] -> []\n", + "* General case\n", + " * Input: ['ram', 'act', 'arm', 'bat', 'cat', 'tab']\n", + " * Result: ['arm', 'ram', 'act', 'cat', 'bat', 'tab']" + ] + }, + { + "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": [ + "from collections import OrderedDict\n", + "\n", + "\n", + "class Anagram(object):\n", + "\n", + " def group_anagrams(self, items):\n", + " # TODO: Implement me\n", + " pass" + ] + }, + { + "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": null, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "# %load test_anagrams.py\n", + "from nose.tools import assert_equal, assert_raises\n", + "\n", + "\n", + "class TestAnagrams(object):\n", + "\n", + " def test_group_anagrams(self):\n", + " anagram = Anagram()\n", + " assert_raises(TypeError, anagram.group_anagrams, None)\n", + " data = ['ram', 'act', 'arm', 'bat', 'cat', 'tab']\n", + " expected = ['ram', 'arm', 'act', 'cat', 'bat', 'tab']\n", + " assert_equal(anagram.group_anagrams(data), expected)\n", + "\n", + " print('Success: test_group_anagrams')\n", + "\n", + "\n", + "def main():\n", + " test = TestAnagrams()\n", + " test.test_group_anagrams()\n", + "\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 3", + "language": "python", + "name": "python3" + }, + "language_info": { + "codemirror_mode": { + "name": "ipython", + "version": 3 + }, + "file_extension": ".py", + "mimetype": "text/x-python", + "name": "python", + "nbconvert_exporter": "python", + "pygments_lexer": "ipython3", + "version": "3.5.0" + } + }, + "nbformat": 4, + "nbformat_minor": 0 +} diff --git a/sorting_searching/anagrams/anagrams_solution.ipynb b/sorting_searching/anagrams/anagrams_solution.ipynb new file mode 100644 index 0000000..da04897 --- /dev/null +++ b/sorting_searching/anagrams/anagrams_solution.ipynb @@ -0,0 +1,220 @@ +{ + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)." + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Solution Notebook" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Problem: Sort an array of strings so all anagrams are next to each other.\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", + "* Are there any other sorting requirements other than the grouping of anagrams?\n", + " * No\n", + "* Can we assume the inputs are valid?\n", + " * No\n", + "* Can we assume this fits memory?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "* None -> Exception\n", + "* [] -> []\n", + "* General case\n", + " * Input: ['ram', 'act', 'arm', 'bat', 'cat', 'tab']\n", + " * Result: ['arm', 'ram', 'act', 'cat', 'bat', 'tab']" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Algorithm\n", + "\n", + "
\n",
+    "Input: ['ram', 'act', 'arm', 'bat', 'cat', 'tab']\n",
+    "\n",
+    "Sort the chars for each item:\n",
+    "\n",
+    "'ram' -> 'amr'\n",
+    "'act' -> 'act'\n",
+    "'arm' -> 'amr'\n",
+    "'abt' -> 'bat'\n",
+    "'cat' -> 'act'\n",
+    "'abt' -> 'tab'\n",
+    "\n",
+    "Use a map of sorted chars to each item to group anagrams:\n",
+    "\n",
+    "{\n",
+    "    'amr': ['ram', 'arm'], \n",
+    "    'act': ['act', 'cat'], \n",
+    "    'abt': ['bat', 'tab']\n",
+    "}\n",
+    "\n",
+    "Result: ['arm', 'ram', 'act', 'cat', 'bat', 'tab']\n",
+    "
\n", + "\n", + "Complexity:\n", + "* Time: O(k * n), due to the modified bucket sort\n", + "* Space: O(n)" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Code" + ] + }, + { + "cell_type": "code", + "execution_count": 1, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "from collections import OrderedDict\n", + "\n", + "\n", + "class Anagram(object):\n", + "\n", + " def group_anagrams(self, items):\n", + " if items is None:\n", + " raise TypeError('items cannot be None')\n", + " if not items:\n", + " return items\n", + " anagram_map = OrderedDict()\n", + " for item in items:\n", + " # Use a tuple, which is hashable and\n", + " # serves as the key in anagram_map\n", + " sorted_chars = tuple(sorted(item))\n", + " if sorted_chars in anagram_map:\n", + " anagram_map[sorted_chars].append(item)\n", + " else:\n", + " anagram_map[sorted_chars] = [item]\n", + " result = []\n", + " for value in anagram_map.values():\n", + " result.extend(value)\n", + " return result" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Unit Test" + ] + }, + { + "cell_type": "code", + "execution_count": 2, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Overwriting test_anagrams.py\n" + ] + } + ], + "source": [ + "%%writefile test_anagrams.py\n", + "from nose.tools import assert_equal, assert_raises\n", + "\n", + "\n", + "class TestAnagrams(object):\n", + "\n", + " def test_group_anagrams(self):\n", + " anagram = Anagram()\n", + " assert_raises(TypeError, anagram.group_anagrams, None)\n", + " data = ['ram', 'act', 'arm', 'bat', 'cat', 'tab']\n", + " expected = ['ram', 'arm', 'act', 'cat', 'bat', 'tab']\n", + " assert_equal(anagram.group_anagrams(data), expected)\n", + "\n", + " print('Success: test_group_anagrams')\n", + "\n", + "\n", + "def main():\n", + " test = TestAnagrams()\n", + " test.test_group_anagrams()\n", + "\n", + "\n", + "if __name__ == '__main__':\n", + " main()" + ] + }, + { + "cell_type": "code", + "execution_count": 3, + "metadata": { + "collapsed": false + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Success: test_group_anagrams\n" + ] + } + ], + "source": [ + "%run -i test_anagrams.py" + ] + } + ], + "metadata": { + "kernelspec": { + "display_name": "Python 3", + "language": "python", + "name": "python3" + }, + "language_info": { + "codemirror_mode": { + "name": "ipython", + "version": 3 + }, + "file_extension": ".py", + "mimetype": "text/x-python", + "name": "python", + "nbconvert_exporter": "python", + "pygments_lexer": "ipython3", + "version": "3.5.0" + } + }, + "nbformat": 4, + "nbformat_minor": 0 +} diff --git a/sorting_searching/anagrams/test_anagrams.py b/sorting_searching/anagrams/test_anagrams.py new file mode 100644 index 0000000..6395b0d --- /dev/null +++ b/sorting_searching/anagrams/test_anagrams.py @@ -0,0 +1,22 @@ +from nose.tools import assert_equal, assert_raises + + +class TestAnagrams(object): + + def test_group_anagrams(self): + anagram = Anagram() + assert_raises(TypeError, anagram.group_anagrams, None) + data = ['ram', 'act', 'arm', 'bat', 'cat', 'tab'] + expected = ['ram', 'arm', 'act', 'cat', 'bat', 'tab'] + assert_equal(anagram.group_anagrams(data), expected) + + print('Success: test_group_anagrams') + + +def main(): + test = TestAnagrams() + test.test_group_anagrams() + + +if __name__ == '__main__': + main() \ No newline at end of file