mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
synced 2024-03-22 13:11:13 +08:00
Add prod three challenge
This commit is contained in:
Donne Martin
parent
c3b6ef0376
commit
01b0d949a9
0
online_judges/prod_three/__init__.py
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0
online_judges/prod_three/__init__.py
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171
online_judges/prod_three/prod_three_challenge.ipynb
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171
online_judges/prod_three/prod_three_challenge.ipynb
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@ -0,0 +1,171 @@
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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: Find the highest product of three numbers in a list.\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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"* Is the input a list of integers?\n",
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" * Yes\n",
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"* Can we get negative inputs?\n",
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" * Yes\n",
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"* Can there be duplicate entires in the input?\n",
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" * Yes\n",
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"* Will there always be at least three integers?\n",
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" * No\n",
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"* Can we assume the inputs are valid?\n",
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" * No, check for None input\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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"* None -> TypeError\n",
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"* Less than three ints -> ValueError\n",
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"* [5, -2, 3] -> -30\n",
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"* [5, -2, 3, 1, -1, 4] -> 60"
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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 max_prod_three(self, array):\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_prod_three.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 TestProdThree(object):\n",
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"\n",
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" def test_prod_three(self):\n",
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" solution = Solution()\n",
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" assert_raises(TypeError, solution.max_prod_three, None)\n",
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" assert_raises(ValueError, solution.max_prod_three, [1, 2])\n",
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" assert_equal(solution.max_prod_three([5, -2, 3]), -30)\n",
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" assert_equal(solution.max_prod_three([5, -2, 3, 1, -1, 4]), 60)\n",
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" print('Success: test_prod_three')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestProdThree()\n",
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" test.test_prod_three()\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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279
online_judges/prod_three/prod_three_solution.ipynb
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online_judges/prod_three/prod_three_solution.ipynb
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@ -0,0 +1,279 @@
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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: Find the highest product of three numbers in a list.\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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"* Is the input a list of integers?\n",
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" * Yes\n",
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"* Can we get negative inputs?\n",
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" * Yes\n",
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"* Can there be duplicate entires in the input?\n",
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" * Yes\n",
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"* Will there always be at least three integers?\n",
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" * No\n",
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"* Can we assume the inputs are valid?\n",
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" * No, check for None input\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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"* None -> TypeError\n",
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"* Less than three ints -> ValueError\n",
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"* [5, -2, 3] -> -30\n",
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"* [5, -2, 3, 1, -1, 4] -> 60"
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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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"### Brute force:\n",
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"\n",
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"Use three loops and multiple each numbers.\n",
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"\n",
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"Complexity:\n",
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"* Time: O(n^3)\n",
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"* Space: O(1)\n",
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"\n",
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"### Sorting:\n",
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"\n",
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"Sort the list, multiply the last three elements.\n",
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"\n",
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"Complexity:\n",
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"* Time: O(n log(n))\n",
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"* Space: O(1)\n",
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"\n",
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"### Greedy:\n",
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"\n",
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"<pre>\n",
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" 0 1 2 3 4 5\n",
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"[5, -2, 3, 1, -1, 4] -> 60\n",
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"\n",
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"max_prod_of_three = -30\n",
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"max_prod_of_two = -10\n",
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"max_num = 5\n",
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"min_prod_of_two = -10\n",
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"min_num = -2\n",
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"\n",
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" 0 1 2 3 4 5\n",
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"[5, -2, 3, 1, -1, 4] -> 60\n",
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" ^\n",
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"max_prod_of_three = -30\n",
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"max_prod_of_two = 15\n",
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"max_num = 5\n",
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"min_prod_of_two = -10\n",
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"min_num = -2\n",
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"\n",
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" 0 1 2 3 4 5\n",
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"[5, -2, 3, 1, -1, 4] -> 60\n",
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" ^\n",
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"max_prod_of_three = 15\n",
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"max_prod_of_two = 15\n",
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"max_num = 5\n",
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"min_prod_of_two = -10\n",
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"min_num = -2\n",
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"\n",
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" 0 1 2 3 4 5\n",
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"[5, -2, 3, 1, -1, 4] -> 60\n",
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" ^\n",
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"max_prod_of_three = 15\n",
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"max_prod_of_two = 15\n",
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"max_num = 5\n",
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"min_prod_of_two = -10\n",
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"min_num = -2\n",
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"\n",
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" 0 1 2 3 4 5\n",
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"[5, -2, 3, 1, -1, 4] -> 60\n",
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" ^\n",
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"max_prod_of_three = 60\n",
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"max_prod_of_two = 15\n",
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"max_num = 5\n",
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"min_prod_of_two = -10\n",
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"min_num = -2\n",
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"</pre>\n",
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"\n",
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"Complexity:\n",
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"* Time: O(n)\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 max_prod_three_nlogn(self, array):\n",
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" if array is None:\n",
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" raise TypeError('array cannot be None')\n",
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" if len(array) < 3:\n",
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" raise ValueError('array must have 3 or more ints')\n",
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" array.sort()\n",
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" product = 1\n",
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" for item in array[-3:]:\n",
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" product *= item\n",
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" return product\n",
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"\n",
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" def max_prod_three(self, array):\n",
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" if array is None:\n",
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" raise TypeError('array cannot be None')\n",
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" if len(array) < 3:\n",
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" raise ValueError('array must have 3 or more ints')\n",
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" curr_max_prod_three = array[0] * array[1] * array[2]\n",
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" max_prod_two = array[0] * array[1]\n",
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" min_prod_two = array[0] * array[1]\n",
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" max_num = max(array[0], array[1])\n",
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" min_num = min(array[0], array[1])\n",
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" for i in range(2, len(array)):\n",
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" curr_max_prod_three = max(curr_max_prod_three,\n",
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" max_prod_two * array[i],\n",
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" min_prod_two * array[i])\n",
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" max_prod_two = max(max_prod_two,\n",
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" max_num * array[i],\n",
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" min_num * array[i])\n",
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" min_prod_two = min(min_prod_two,\n",
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" max_num * array[i],\n",
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" min_num * array[i])\n",
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" max_num = max(max_num, array[i])\n",
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" min_num = min(min_num, array[i])\n",
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" return curr_max_prod_three"
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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_prod_three.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_prod_three.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 TestProdThree(object):\n",
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"\n",
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" def test_prod_three(self):\n",
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" solution = Solution()\n",
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" assert_raises(TypeError, solution.max_prod_three, None)\n",
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" assert_raises(ValueError, solution.max_prod_three, [1, 2])\n",
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" assert_equal(solution.max_prod_three([5, -2, 3]), -30)\n",
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" assert_equal(solution.max_prod_three([5, -2, 3, 1, -1, 4]), 60)\n",
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" print('Success: test_prod_three')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestProdThree()\n",
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" test.test_prod_three()\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_prod_three\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_prod_three.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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21
online_judges/prod_three/test_prod_three.py
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21
online_judges/prod_three/test_prod_three.py
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from nose.tools import assert_equal, assert_raises
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class TestProdThree(object):
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def test_prod_three(self):
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solution = Solution()
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assert_raises(TypeError, solution.max_prod_three, None)
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assert_raises(ValueError, solution.max_prod_three, [1, 2])
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assert_equal(solution.max_prod_three([5, -2, 3]), -30)
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assert_equal(solution.max_prod_three([5, -2, 3, 1, -1, 4]), 60)
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print('Success: test_prod_three')
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def main():
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test = TestProdThree()
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test.test_prod_three()
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if __name__ == '__main__':
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main()
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