mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
synced 2024-03-22 13:11:13 +08:00
Add nim challenge
This commit is contained in:
Donne Martin
parent
01b0d949a9
commit
fbe2fcc167
0
online_judges/nim/__init__.py
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0
online_judges/nim/__init__.py
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179
online_judges/nim/nim_challenge.ipynb
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179
online_judges/nim/nim_challenge.ipynb
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@ -0,0 +1,179 @@
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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: Determine whether you can win the Nim game given the remaining stones.\n",
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"\n",
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"See the [LeetCode](https://leetcode.com/problems/nim-game/) problem page.\n",
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"\n",
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"You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the winner. You will take the first turn to remove the stones.\n",
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"\n",
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"Both of you are very clever and have optimal strategies for the game. Write a function to determine whether you can win the game given the number of stones in the heap.\n",
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"\n",
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"For example, if there are 4 stones in the heap, then you will never win the game: no matter 1, 2, or 3 stones you remove, the last stone will always be removed by your friend.\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 an int?\n",
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" * Yes\n",
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"* Is the output a boolean?\n",
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" * Yes\n",
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"* Can we assume the inputs are valid?\n",
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" * No\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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"* 1, 2, or 3 -> True\n",
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"* 4 -> False\n",
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"* 7 -> True\n",
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"* 40 -> False"
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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 can_win_nim(self, num_stones_left):\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_can_win_nim.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 TestSolution(object):\n",
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"\n",
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" def test_can_win_nim(self):\n",
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" solution = Solution()\n",
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" assert_raises(TypeError, solution.can_win_nim, None)\n",
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" assert_equal(solution.can_win_nim(1), True)\n",
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" assert_equal(solution.can_win_nim(2), True)\n",
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" assert_equal(solution.can_win_nim(3), True)\n",
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" assert_equal(solution.can_win_nim(4), False)\n",
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" assert_equal(solution.can_win_nim(7), True)\n",
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" assert_equal(solution.can_win_nim(40), False)\n",
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" print('Success: test_can_win_nim')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestSolution()\n",
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" test.test_can_win_nim()\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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192
online_judges/nim/nim_solution.ipynb
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192
online_judges/nim/nim_solution.ipynb
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@ -0,0 +1,192 @@
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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: Determine whether you can win the Nim game given the remaining stones.\n",
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"\n",
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"See the [LeetCode](https://leetcode.com/problems/nim-game/) problem page.\n",
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"\n",
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"You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the winner. You will take the first turn to remove the stones.\n",
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"\n",
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"Both of you are very clever and have optimal strategies for the game. Write a function to determine whether you can win the game given the number of stones in the heap.\n",
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"\n",
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"For example, if there are 4 stones in the heap, then you will never win the game: no matter 1, 2, or 3 stones you remove, the last stone will always be removed by your friend.\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 an int?\n",
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" * Yes\n",
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"* Is the output a boolean?\n",
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" * Yes\n",
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"* Can we assume the inputs are valid?\n",
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" * Yes\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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"* 1, 2, or 3 -> True\n",
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"* 4 -> False\n",
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"* 7 -> True\n",
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"* 40 -> False"
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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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"This is somewhat of a one-trick puzzle, where the only way you can lose if you take the first stone while playing optimally is if the number of remaining stones is divisible by 4.\n",
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"\n",
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"Complexity:\n",
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"* Time: O(1)\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 can_win_nim(self, num_stones_left):\n",
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" return num_stones_left % 4 != 0"
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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_can_win_nim.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_can_win_nim.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 TestSolution(object):\n",
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"\n",
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" def test_can_win_nim(self):\n",
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" solution = Solution()\n",
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" assert_raises(TypeError, solution.can_win_nim, None)\n",
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" assert_equal(solution.can_win_nim(1), True)\n",
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" assert_equal(solution.can_win_nim(2), True)\n",
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" assert_equal(solution.can_win_nim(3), True)\n",
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" assert_equal(solution.can_win_nim(4), False)\n",
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" assert_equal(solution.can_win_nim(7), True)\n",
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" assert_equal(solution.can_win_nim(40), False)\n",
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" print('Success: test_can_win_nim')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestSolution()\n",
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" test.test_can_win_nim()\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_can_win_nim\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_can_win_nim.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": "3.5.0"
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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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24
online_judges/nim/test_can_win_nim.py
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24
online_judges/nim/test_can_win_nim.py
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@ -0,0 +1,24 @@
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from nose.tools import assert_equal, assert_raises
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class TestSolution(object):
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def test_can_win_nim(self):
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solution = Solution()
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assert_raises(TypeError, solution.can_win_nim, None)
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assert_equal(solution.can_win_nim(1), True)
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assert_equal(solution.can_win_nim(2), True)
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assert_equal(solution.can_win_nim(3), True)
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assert_equal(solution.can_win_nim(4), False)
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assert_equal(solution.can_win_nim(7), True)
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assert_equal(solution.can_win_nim(40), False)
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print('Success: test_can_win_nim')
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def main():
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test = TestSolution()
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test.test_can_win_nim()
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if __name__ == '__main__':
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main()
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