From fed90d0fd86a02dc41e69c1807c229bce85dd4aa Mon Sep 17 00:00:00 2001 From: Donne Martin Date: Wed, 29 Mar 2017 04:41:24 -0400 Subject: [PATCH] Add sub two challenge --- math_probability/sub_two/__init__.py | 0 .../sub_two/sub_two_challenge.ipynb | 167 ++++++++++++++ .../sub_two/sub_two_solution.ipynb | 206 ++++++++++++++++++ math_probability/sub_two/test_sub_two.py | 22 ++ 4 files changed, 395 insertions(+) create mode 100644 math_probability/sub_two/__init__.py create mode 100644 math_probability/sub_two/sub_two_challenge.ipynb create mode 100644 math_probability/sub_two/sub_two_solution.ipynb create mode 100644 math_probability/sub_two/test_sub_two.py diff --git a/math_probability/sub_two/__init__.py b/math_probability/sub_two/__init__.py new file mode 100644 index 0000000..e69de29 diff --git a/math_probability/sub_two/sub_two_challenge.ipynb b/math_probability/sub_two/sub_two_challenge.ipynb new file mode 100644 index 0000000..704e278 --- /dev/null +++ b/math_probability/sub_two/sub_two_challenge.ipynb @@ -0,0 +1,167 @@ +{ + "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: Find the difference of two integers without using the + or - sign.\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", + "* Can we assume the inputs are valid?\n", + " * No, check for None\n", + "* Can we assume this fits memory?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "
\n",
+    "* None input -> TypeError\n",
+    "* 7, 5 -> 2\n",
+    "* -5, -7 -> 2\n",
+    "* -5, 7 -> -12\n",
+    "* 5, -7 -> 12\n",
+    "
" + ] + }, + { + "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": [ + "class Solution(object):\n", + "\n", + " def sub_two(self, val):\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_sub_two.py\n", + "from nose.tools import assert_equal, assert_raises\n", + "\n", + "\n", + "class TestSubTwo(object):\n", + "\n", + " def test_sub_two(self):\n", + " solution = Solution()\n", + " assert_raises(TypeError, solution.sub_two, None)\n", + " assert_equal(solution.sub_two(7, 5), 2)\n", + " assert_equal(solution.sub_two(-5, -7), 2)\n", + " assert_equal(solution.sub_two(-5, 7), -12)\n", + " assert_equal(solution.sub_two(5, -7), 12)\n", + " print('Success: test_sub_two')\n", + "\n", + "\n", + "def main():\n", + " test = TestSubTwo()\n", + " test.test_sub_two()\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/math_probability/sub_two/sub_two_solution.ipynb b/math_probability/sub_two/sub_two_solution.ipynb new file mode 100644 index 0000000..4593615 --- /dev/null +++ b/math_probability/sub_two/sub_two_solution.ipynb @@ -0,0 +1,206 @@ +{ + "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: Find the difference of two integers without using the + or - sign.\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", + "* Can we assume the inputs are valid?\n", + " * No, check for None\n", + "* Can we assume this fits memory?\n", + " * Yes" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Test Cases\n", + "\n", + "
\n",
+    "* None input -> TypeError\n",
+    "* 7, 5 -> 2\n",
+    "* -5, -7 -> 2\n",
+    "* -5, 7 -> -12\n",
+    "* 5, -7 -> 12\n",
+    "
" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Algorithm\n", + "\n", + "We'll look at the following example, subtracting a and b:\n", + "\n", + "
\n",
+    "a 0110 = 6 \n",
+    "b 0101 = 5\n",
+    "
\n", + "\n", + "First, subtract a and b, without worrying about the borrow (0-0=0, 0-1=1, 1-1=0):\n", + "\n", + "result = a ^ b = 0011\n", + "\n", + "Next, calculate the borrow (0-1=1). We'll need to left shift one to prepare for the next iteration when we move to the next most significant bit:\n", + "\n", + "~a = 1001\n", + " b = 0101\n", + "~a & b = 0001\n", + "\n", + "borrow = (~a&b) << 1 = 0010\n", + "\n", + "If the borrow is not zero, we'll need to subtract the borrow from the result. Recusively call the function, passing in result and borrow.\n", + "\n", + "Complexity:\n", + "* Time: O(b), where b is the number of bits\n", + "* Space: O(b), where b is the number of bits" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Code" + ] + }, + { + "cell_type": "code", + "execution_count": 1, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "class Solution(object):\n", + "\n", + " def sub_two(self, a, b):\n", + " if a is None or b is None:\n", + " raise TypeError('a or b cannot be None')\n", + " result = a ^ b;\n", + " borrow = (~a & b) << 1\n", + " if borrow != 0:\n", + " return self.sub_two(result, borrow)\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_sub_two.py\n" + ] + } + ], + "source": [ + "%%writefile test_sub_two.py\n", + "from nose.tools import assert_equal, assert_raises\n", + "\n", + "\n", + "class TestSubTwo(object):\n", + "\n", + " def test_sub_two(self):\n", + " solution = Solution()\n", + " assert_raises(TypeError, solution.sub_two, None)\n", + " assert_equal(solution.sub_two(7, 5), 2)\n", + " assert_equal(solution.sub_two(-5, -7), 2)\n", + " assert_equal(solution.sub_two(-5, 7), -12)\n", + " assert_equal(solution.sub_two(5, -7), 12)\n", + " print('Success: test_sub_two')\n", + "\n", + "\n", + "def main():\n", + " test = TestSubTwo()\n", + " test.test_sub_two()\n", + "\n", + "\n", + "if __name__ == '__main__':\n", + " main()" + ] + }, + { + "cell_type": "code", + "execution_count": 3, + "metadata": { + "collapsed": false, + "scrolled": true + }, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "Success: test_sub_two\n" + ] + } + ], + "source": [ + "%run -i test_sub_two.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/math_probability/sub_two/test_sub_two.py b/math_probability/sub_two/test_sub_two.py new file mode 100644 index 0000000..f022a3f --- /dev/null +++ b/math_probability/sub_two/test_sub_two.py @@ -0,0 +1,22 @@ +from nose.tools import assert_equal, assert_raises + + +class TestSubTwo(object): + + def test_sub_two(self): + solution = Solution() + assert_raises(TypeError, solution.sub_two, None) + assert_equal(solution.sub_two(7, 5), 2) + assert_equal(solution.sub_two(-5, -7), 2) + assert_equal(solution.sub_two(-5, 7), -12) + assert_equal(solution.sub_two(5, -7), 12) + print('Success: test_sub_two') + + +def main(): + test = TestSubTwo() + test.test_sub_two() + + +if __name__ == '__main__': + main() \ No newline at end of file