mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
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Add island perimeter challenge
This commit is contained in:
Donne Martin
parent
f3aecac778
commit
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0
online_judges/island_perimeter/__init__.py
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0
online_judges/island_perimeter/__init__.py
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188
online_judges/island_perimeter/island_perimeter_challenge.ipynb
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188
online_judges/island_perimeter/island_perimeter_challenge.ipynb
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@ -0,0 +1,188 @@
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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"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)."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Challenge Notebook"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Problem: Island Perimeter.\n",
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"\n",
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"See the [LeetCode](https://leetcode.com/problems/island-perimeter/) problem page.\n",
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"\n",
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"You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and there is exactly one island (i.e., one or more connected land cells). The island doesn't have \"lakes\" (water inside that isn't connected to the water around the island). One cell is a square with side length 1. The grid is rectangular, width and height don't exceed 100. Determine the perimeter of the island.\n",
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"\n",
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"Example:\n",
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"\n",
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"<pre>\n",
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"[[0,1,0,0],\n",
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" [1,1,1,0],\n",
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" [0,1,0,0],\n",
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" [1,1,0,0]]\n",
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"</pre>\n",
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"\n",
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"Answer: 16\n",
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"\n",
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"* [Constraints](#Constraints)\n",
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"* [Test Cases](#Test-Cases)\n",
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"* [Algorithm](#Algorithm)\n",
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"* [Code](#Code)\n",
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"* [Unit Test](#Unit-Test)\n",
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"* [Solution Notebook](#Solution-Notebook)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Constraints\n",
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"\n",
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"* Can we assume the inputs are valid?\n",
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" * No, check for None\n",
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"* Can we assume this fits memory?\n",
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" * Yes"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Test Cases\n",
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"\n",
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"<pre>\n",
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"* None -> TypeError\n",
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"* [[1, 0]] -> 4\n",
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"* [[0, 1, 0, 0],\n",
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" [1, 1, 1, 0],\n",
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" [0, 1, 0, 0],\n",
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" [1, 1, 0, 0]] -> 16\n",
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"</pre>"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Algorithm\n",
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"\n",
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"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."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Code"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"class Solution(object):\n",
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"\n",
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" def island_perimeter(self, grid):\n",
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" # TODO: Implement me\n",
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" pass"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Unit Test"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"**The following unit test is expected to fail until you solve the challenge.**"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"# %load test_island_perimeter.py\n",
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"from nose.tools import assert_equal, assert_raises\n",
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"\n",
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"\n",
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"class TestIslandPerimeter(object):\n",
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"\n",
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" def test_island_perimeter(self):\n",
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" solution = Solution()\n",
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" assert_raises(TypeError, solution.island_perimeter, None)\n",
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" data = [[1, 0]]\n",
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" expected = 4\n",
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" assert_equal(solution.island_perimeter(data), expected)\n",
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" data = [[0, 1, 0, 0],\n",
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" [1, 1, 1, 0],\n",
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" [0, 1, 0, 0],\n",
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" [1, 1, 0, 0]]\n",
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" expected = 16\n",
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" assert_equal(solution.island_perimeter(data), expected)\n",
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" print('Success: test_island_perimeter')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestIslandPerimeter()\n",
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" test.test_island_perimeter()\n",
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"\n",
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"\n",
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"if __name__ == '__main__':\n",
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" main()"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Solution Notebook\n",
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"\n",
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"Review the [Solution Notebook]() for a discussion on algorithms and code solutions."
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.5.0"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 0
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}
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223
online_judges/island_perimeter/island_perimeter_solution.ipynb
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online_judges/island_perimeter/island_perimeter_solution.ipynb
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@ -0,0 +1,223 @@
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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"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)."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Solution Notebook"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Problem: Island Perimeter.\n",
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"\n",
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"See the [LeetCode](https://leetcode.com/problems/island-perimeter/) problem page.\n",
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"\n",
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"You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and there is exactly one island (i.e., one or more connected land cells). The island doesn't have \"lakes\" (water inside that isn't connected to the water around the island). One cell is a square with side length 1. The grid is rectangular, width and height don't exceed 100. Determine the perimeter of the island.\n",
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"\n",
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"Example:\n",
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"\n",
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"<pre>\n",
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"[[0,1,0,0],\n",
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" [1,1,1,0],\n",
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" [0,1,0,0],\n",
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" [1,1,0,0]]\n",
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"</pre>\n",
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"\n",
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"Answer: 16\n",
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"\n",
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"* [Constraints](#Constraints)\n",
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"* [Test Cases](#Test-Cases)\n",
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"* [Algorithm](#Algorithm)\n",
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"* [Code](#Code)\n",
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"* [Unit Test](#Unit-Test)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Constraints\n",
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"\n",
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"* Can we assume the inputs are valid?\n",
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" * No, check for None\n",
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"* Can we assume this fits memory?\n",
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" * Yes"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Test Cases\n",
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"\n",
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"<pre>\n",
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"* None -> TypeError\n",
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"* [[1, 0]] -> 4\n",
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"* [[0, 1, 0, 0],\n",
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" [1, 1, 1, 0],\n",
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" [0, 1, 0, 0],\n",
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" [1, 1, 0, 0]] -> 16\n",
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"</pre>"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Algorithm\n",
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"\n",
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"For each cell in the grid:\n",
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"* Check left, right, up, down\n",
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" * For each check, if we are at the edge or the cell we are checking is land, increment sides\n",
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"\n",
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"Complexity:\n",
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"* Time: O(rows * cols)\n",
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"* Space: O(1)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Code"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 1,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"class Solution(object):\n",
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"\n",
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" def island_perimeter(self, grid):\n",
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" if grid is None:\n",
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" raise TypeError('grid cannot be None')\n",
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" sides = 0\n",
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" num_rows = len(grid)\n",
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" num_cols = len(grid[0])\n",
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" for i in range(num_rows):\n",
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" for j in range(num_cols):\n",
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" if grid[i][j] == 1:\n",
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" # Check left\n",
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" if j == 0 or grid[i][j - 1] == 0:\n",
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" sides += 1\n",
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" # Check right\n",
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" if j == num_cols - 1 or grid[i][j + 1] == 0:\n",
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" sides += 1\n",
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" # Check up\n",
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" if i == 0 or grid[i - 1][j] == 0:\n",
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" sides += 1\n",
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" # Check down\n",
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" if i == num_rows - 1 or grid[i + 1][j] == 0:\n",
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" sides += 1\n",
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" return sides"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Unit Test"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 2,
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"metadata": {
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"collapsed": false
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},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"Overwriting test_island_perimeter.py\n"
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]
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}
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],
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"source": [
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"%%writefile test_island_perimeter.py\n",
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"from nose.tools import assert_equal, assert_raises\n",
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"\n",
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"\n",
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"class TestIslandPerimeter(object):\n",
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"\n",
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" def test_island_perimeter(self):\n",
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" solution = Solution()\n",
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" assert_raises(TypeError, solution.island_perimeter, None)\n",
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" data = [[1, 0]]\n",
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" expected = 4\n",
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" assert_equal(solution.island_perimeter(data), expected)\n",
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" data = [[0, 1, 0, 0],\n",
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" [1, 1, 1, 0],\n",
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" [0, 1, 0, 0],\n",
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" [1, 1, 0, 0]]\n",
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" expected = 16\n",
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" assert_equal(solution.island_perimeter(data), expected)\n",
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" print('Success: test_island_perimeter')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestIslandPerimeter()\n",
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" test.test_island_perimeter()\n",
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"\n",
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"\n",
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"if __name__ == '__main__':\n",
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" main()"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 3,
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"metadata": {
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"collapsed": false
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},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"Success: test_island_perimeter\n"
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]
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}
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],
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"source": [
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"%run -i test_island_perimeter.py"
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.4.3"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 0
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}
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27
online_judges/island_perimeter/test_island_perimeter.py
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27
online_judges/island_perimeter/test_island_perimeter.py
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from nose.tools import assert_equal, assert_raises
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class TestIslandPerimeter(object):
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def test_island_perimeter(self):
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solution = Solution()
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assert_raises(TypeError, solution.island_perimeter, None)
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data = [[1, 0]]
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expected = 4
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assert_equal(solution.island_perimeter(data), expected)
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data = [[0, 1, 0, 0],
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[1, 1, 1, 0],
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[0, 1, 0, 0],
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[1, 1, 0, 0]]
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expected = 16
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assert_equal(solution.island_perimeter(data), expected)
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print('Success: test_island_perimeter')
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def main():
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test = TestIslandPerimeter()
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test.test_island_perimeter()
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if __name__ == '__main__':
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main()
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