65 lines
2.7 KiB
Markdown
65 lines
2.7 KiB
Markdown
|
---
|
|||
|
|
title: Josephus problem
|
|||
|
|
id: 5a23c84252665b21eecc7ec5
|
|||
|
|
challengeType: 5
|
|||
|
|
videoUrl: ''
|
|||
|
|
localeTitle: 约瑟夫斯问题
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## Description
|
|||
|
|
<section id="description"> <a href="https://en.wikipedia.org/wiki/Josephus problem">约瑟夫斯问题</a>是一个严峻描述的数学难题：$ n $囚犯站在一个圆圈上，顺序编号从$ 0 $到$ n-1 $。一名刽子手沿着圈子走，从囚犯$ 0 $开始，移走每个$ k $囚犯并杀死他。随着过程的继续，圆圈变得越来越小，直到只剩下一个囚犯，然后被释放。例如，如果$ n = 5 $囚犯和$ k = 2 $，囚犯被杀的命令（我们称之为“杀戮序列”）将是1,3,0和4，幸存者将是＃2。鉴于任何<big>$ n，k> 0 $</big> ，找出哪个囚犯将成为最后的幸存者。在一个这样的事件中，有41个囚犯和每3 <sup>次</sup>囚犯被杀死<big>（$ K = 3 $）。</big>其中有一个聪明的名字约瑟夫斯，他解决了这个问题，站在幸存的位置，并继续讲述这个故事。他是哪个号码？写一个函数，以囚犯的初始数量和'k'作为参数，并返回幸存的囚犯的数量。 </section>
|
|||
|
|
|
|||
|
|
## Instructions
|
|||
|
|
<section id="instructions">
|
|||
|
|
</section>
|
|||
|
|
|
|||
|
|
## Tests
|
|||
|
|
<section id='tests'>
|
|||
|
|
|
|||
|
|
```yml
|
|||
|
|
tests:
|
|||
|
|
- text: <code>josephus</code>应该是一个功能。
|
|||
|
|
testString: 'assert(typeof josephus=="function","<code>josephus</code> should be a function.");'
|
|||
|
|
- text: '<code>josephus(30,3)</code>应该返回一个数字。'
|
|||
|
|
testString: 'assert(typeof josephus(30,3)=="number","<code>josephus(30,3)</code> should return a number.");'
|
|||
|
|
- text: '<code>josephus(30,3)</code>应该回<code>29</code> 。'
|
|||
|
|
testString: 'assert.equal(josephus(30,3),29,"<code>josephus(30,3)</code> should return <code>29</code>.");'
|
|||
|
|
- text: '<code>josephus(30,5)</code>应该返回<code>3</code> 。'
|
|||
|
|
testString: 'assert.equal(josephus(30,5),3,"<code>josephus(30,5)</code> should return <code>3</code>.");'
|
|||
|
|
- text: '<code>josephus(20,2)</code>应该返回<code>9</code> 。'
|
|||
|
|
testString: 'assert.equal(josephus(20,2),9,"<code>josephus(20,2)</code> should return <code>9</code>.");'
|
|||
|
|
- text: '<code>josephus(17,6)</code>应该回归<code>2</code> 。'
|
|||
|
|
testString: 'assert.equal(josephus(17,6),2,"<code>josephus(17,6)</code> should return <code>2</code>.");'
|
|||
|
|
- text: '<code>josephus(29,4)</code>应该返回<code>2</code> 。'
|
|||
|
|
testString: 'assert.equal(josephus(29,4),2,"<code>josephus(29,4)</code> should return <code>2</code>.");'
|
|||
|
|
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
</section>
|
|||
|
|
|
|||
|
|
## Challenge Seed
|
|||
|
|
<section id='challengeSeed'>
|
|||
|
|
|
|||
|
|
<div id='js-seed'>
|
|||
|
|
|
|||
|
|
```js
|
|||
|
|
function josephus (init, kill) {
|
|||
|
|
// Good luck!
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
</section>
|
|||
|
|
|
|||
|
|
## Solution
|
|||
|
|
<section id='solution'>
|
|||
|
|
|
|||
|
|
```js
|
|||
|
|
// solution required
|
|||
|
|
```
|
|||
|
|
</section>
|