From f2587dc29b26b477c4920be4c60c6486b5b33651 Mon Sep 17 00:00:00 2001 From: Donne Martin Date: Wed, 29 Mar 2017 04:31:58 -0400 Subject: [PATCH] Add merge ranges challenge --- online_judges/merge_ranges/__init__.py | 0 .../merge_ranges/merge_ranges_challenge.ipynb | 188 +++++++++++++ .../merge_ranges/merge_ranges_solution.ipynb | 256 ++++++++++++++++++ .../merge_ranges/test_merge_ranges.py | 28 ++ 4 files changed, 472 insertions(+) create mode 100644 online_judges/merge_ranges/__init__.py create mode 100644 online_judges/merge_ranges/merge_ranges_challenge.ipynb create mode 100644 online_judges/merge_ranges/merge_ranges_solution.ipynb create mode 100644 online_judges/merge_ranges/test_merge_ranges.py diff --git a/online_judges/merge_ranges/__init__.py b/online_judges/merge_ranges/__init__.py new file mode 100644 index 0000000..e69de29 diff --git a/online_judges/merge_ranges/merge_ranges_challenge.ipynb b/online_judges/merge_ranges/merge_ranges_challenge.ipynb new file mode 100644 index 0000000..8f955e4 --- /dev/null +++ b/online_judges/merge_ranges/merge_ranges_challenge.ipynb @@ -0,0 +1,188 @@ +{ + "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: Given a list of tuples representing ranges, condense the ranges. \n", + "\n", + "Example: [(2, 3), (3, 5), (7, 9), (8, 10)] -> [(2, 5), (7, 10)]\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 the tuples in sorted order?\n", + " * No\n", + "* Are the tuples ints?\n", + " * Yes\n", + "* Will all tuples have the first element less than the second?\n", + " * Yes\n", + "* Is there an upper bound on the input range?\n", + " * No\n", + "* Is the output a list of tuples?\n", + " * Yes\n", + "* Is the output a new array?\n", + " * Yes\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",
+    "* [] - []\n",
+    "* [(2, 3), (7, 9)] -> [(2, 3), (7, 9)]\n",
+    "* [(2, 3), (3, 5), (7, 9), (8, 10)] -> [(2, 5), (7, 10)]\n",
+    "* [(2, 3), (3, 5), (7, 9), (8, 10), (1, 11)] -> [(1, 11)]\n",
+    "* [(2, 3), (3, 8), (7, 9), (8, 10)] -> [(2, 10)]\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 merge_ranges(self, array):\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_merge_ranges.py\n", + "from nose.tools import assert_equal, assert_raises\n", + "\n", + "\n", + "class TestMergeRanges(object):\n", + "\n", + " def test_merge_ranges(self):\n", + " solution = Solution()\n", + " assert_raises(TypeError, solution.merge_ranges, None)\n", + " assert_equal(solution.merge_ranges([]), [])\n", + " array = [(2, 3), (7, 9)]\n", + " expected = [(2, 3), (7, 9)]\n", + " assert_equal(solution.merge_ranges(array), expected)\n", + " array = [(2, 3), (3, 5), (7, 9), (8, 10)]\n", + " expected = [(2, 5), (7, 10)]\n", + " assert_equal(solution.merge_ranges(array), expected)\n", + " array = [(2, 3), (3, 5), (7, 9), (8, 10), (1, 11)]\n", + " expected = [(1, 11)]\n", + " assert_equal(solution.merge_ranges(array), expected)\n", + " print('Success: test_merge_ranges')\n", + "\n", + "\n", + "def main():\n", + " test = TestMergeRanges()\n", + " test.test_merge_ranges()\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/online_judges/merge_ranges/merge_ranges_solution.ipynb b/online_judges/merge_ranges/merge_ranges_solution.ipynb new file mode 100644 index 0000000..584315a --- /dev/null +++ b/online_judges/merge_ranges/merge_ranges_solution.ipynb @@ -0,0 +1,256 @@ +{ + "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: Given a list of tuples representing ranges, condense the ranges. \n", + "\n", + "Example: [(2, 3), (3, 5), (7, 9), (8, 10)] -> [(2, 5), (7, 10)]\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 the tuples in sorted order?\n", + " * No\n", + "* Are the tuples ints?\n", + " * Yes\n", + "* Will all tuples have the first element less than the second?\n", + " * Yes\n", + "* Is there an upper bound on the input range?\n", + " * No\n", + "* Is the output a list of tuples?\n", + " * Yes\n", + "* Is the output a new array?\n", + " * Yes\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",
+    "* [] - []\n",
+    "* [(2, 3), (7, 9)] -> [(2, 3), (7, 9)]\n",
+    "* [(2, 3), (3, 5), (7, 9), (8, 10)] -> [(2, 5), (7, 10)]\n",
+    "* [(2, 3), (3, 5), (7, 9), (8, 10), (1, 11)] -> [(1, 11)]\n",
+    "* [(2, 3), (3, 8), (7, 9), (8, 10)] -> [(2, 10)]\n",
+    "
" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Algorithm\n", + "\n", + "* Sort the tuples based on start time\n", + "* Check each adjacent tuple to see if they can be merged\n", + "\n", + "
\n",
+    "Case: * [(2, 3), (3, 8), (7, 9), (8, 10)] -> [(2, 10)]\n",
+    "\n",
+    "* Sort by start time (already sorted)\n",
+    "* Add the first tuple to the merged_array\n",
+    "* Loop through each item in sorted_array starting at index 1\n",
+    "    * If there is no overlap\n",
+    "        * Add the current item to merged_array\n",
+    "    * Else\n",
+    "        * Update the last item in merged_array\n",
+    "            * The end time will be the max of merged_array[-1][1] and sorted_array[i][1]\n",
+    "\n",
+    "Start:\n",
+    "                           i\n",
+    "                   0       1       2       3\n",
+    "sorted_array = [(2, 3), (3, 8), (7, 9), (8, 10)]\n",
+    "merged_array = [(2, 3)]\n",
+    "\n",
+    "Overlap with (2, 3), (3, 8):\n",
+    "                           i\n",
+    "                   0       1       2       3\n",
+    "sorted_array = [(2, 3), (3, 8), (7, 9), (8, 10)]\n",
+    "merged_array = [(2, 8)]\n",
+    "\n",
+    "Overlap with (2, 8), (7, 9):\n",
+    "                                   i\n",
+    "                   0       1       2       3\n",
+    "sorted_array = [(2, 3), (3, 8), (7, 9), (8, 10)]\n",
+    "merged_array = [(2, 9)]\n",
+    "\n",
+    "Overlap with (2, 9) (8, 10):\n",
+    "                                   i\n",
+    "                   0       1       2       3\n",
+    "sorted_array = [(2, 3), (3, 8), (7, 9), (8, 10)]\n",
+    "merged_array = [(2, 10)]\n",
+    "
\n", + "\n", + "Complexity:\n", + "* Time: O(n log(n))\n", + "* Space: O(n)" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Code" + ] + }, + { + "cell_type": "code", + "execution_count": 1, + "metadata": { + "collapsed": false + }, + "outputs": [], + "source": [ + "class Solution(object):\n", + "\n", + " def merge_ranges(self, array):\n", + " if array is None:\n", + " raise TypeError('array cannot be None')\n", + " if not array:\n", + " return array\n", + " sorted_array = sorted(array)\n", + " merged_array = [sorted_array[0]]\n", + " for index, item in enumerate(sorted_array):\n", + " if index == 0:\n", + " continue\n", + " start_prev, end_prev = merged_array[-1]\n", + " start_curr, end_curr = item\n", + " if end_prev < start_curr:\n", + " # No overlap, add the entry\n", + " merged_array.append(item)\n", + " else:\n", + " # Overlap, update the previous entry's end value\n", + " merged_array[-1] = (start_prev, max(end_prev, end_curr))\n", + " return merged_array" + ] + }, + { + "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_merge_ranges.py\n" + ] + } + ], + "source": [ + "%%writefile test_merge_ranges.py\n", + "from nose.tools import assert_equal, assert_raises\n", + "\n", + "\n", + "class TestMergeRanges(object):\n", + "\n", + " def test_merge_ranges(self):\n", + " solution = Solution()\n", + " assert_raises(TypeError, solution.merge_ranges, None)\n", + " assert_equal(solution.merge_ranges([]), [])\n", + " array = [(2, 3), (7, 9)]\n", + " expected = [(2, 3), (7, 9)]\n", + " assert_equal(solution.merge_ranges(array), expected)\n", + " array = [(3, 5), (2, 3), (7, 9), (8, 10)]\n", + " expected = [(2, 5), (7, 10)]\n", + " assert_equal(solution.merge_ranges(array), expected)\n", + " array = [(2, 3), (3, 5), (7, 9), (8, 10), (1, 11)]\n", + " expected = [(1, 11)]\n", + " assert_equal(solution.merge_ranges(array), expected)\n", + " print('Success: test_merge_ranges')\n", + "\n", + "\n", + "def main():\n", + " test = TestMergeRanges()\n", + " test.test_merge_ranges()\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_merge_ranges\n" + ] + } + ], + "source": [ + "%run -i test_merge_ranges.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": "3.4.3" + } + }, + "nbformat": 4, + "nbformat_minor": 0 +} diff --git a/online_judges/merge_ranges/test_merge_ranges.py b/online_judges/merge_ranges/test_merge_ranges.py new file mode 100644 index 0000000..5d39cf2 --- /dev/null +++ b/online_judges/merge_ranges/test_merge_ranges.py @@ -0,0 +1,28 @@ +from nose.tools import assert_equal, assert_raises + + +class TestMergeRanges(object): + + def test_merge_ranges(self): + solution = Solution() + assert_raises(TypeError, solution.merge_ranges, None) + assert_equal(solution.merge_ranges([]), []) + array = [(2, 3), (7, 9)] + expected = [(2, 3), (7, 9)] + assert_equal(solution.merge_ranges(array), expected) + array = [(3, 5), (2, 3), (7, 9), (8, 10)] + expected = [(2, 5), (7, 10)] + assert_equal(solution.merge_ranges(array), expected) + array = [(2, 3), (3, 5), (7, 9), (8, 10), (1, 11)] + expected = [(1, 11)] + assert_equal(solution.merge_ranges(array), expected) + print('Success: test_merge_ranges') + + +def main(): + test = TestMergeRanges() + test.test_merge_ranges() + + +if __name__ == '__main__': + main() \ No newline at end of file