2018-10-10 18:03:03 -04:00
|
|
|
|
---
|
|
|
|
|
|
id: 5900f5411000cf542c510053
|
|
|
|
|
|
challengeType: 5
|
|
|
|
|
|
title: 'Problem 469: Empty chairs'
|
|
|
|
|
|
videoUrl: ''
|
|
|
|
|
|
localeTitle: 问题469：空椅子
|
|
|
|
|
|
---
|
|
|
|
|
|
|
|
|
|
|
|
## Description
|
|
|
|
|
|
<section id="description">在一个房间里，N个椅子摆放在圆桌旁。骑士一个接一个地进入房间，随意选择一把可用的空椅子。为了拥有足够的肘部空间，骑士总是在彼此之间留下至少一把空座椅。 <p>当没有任何合适的椅子时，确定空椅子的分数C.我们还将E（N）定义为C的期望值。我们可以验证E（4）= 1/2和E（6）= 5/9。 </p><p>找到E（1018）。将答案四舍五入到小数点后十四位，形式为0.abcdefghijklmn。 </p></section>
|
|
|
|
|
|
|
|
|
|
|
|
## Instructions
|
|
|
|
|
|
<section id="instructions">
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
|
|
## Tests
|
|
|
|
|
|
<section id='tests'>
|
|
|
|
|
|
|
|
|
|
|
|
```yml
|
|
|
|
|
|
tests:
|
|
|
|
|
|
- text: <code>euler469()</code>应该返回0.56766764161831。
|
2020-02-18 01:40:55 +09:00
|
|
|
|
testString: assert.strictEqual(euler469(), 0.56766764161831);
|
2018-10-10 18:03:03 -04:00
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
|
|
## Challenge Seed
|
|
|
|
|
|
<section id='challengeSeed'>
|
|
|
|
|
|
|
|
|
|
|
|
<div id='js-seed'>
|
|
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
|
function euler469() {
|
|
|
|
|
|
// Good luck!
|
|
|
|
|
|
return true;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
euler469();
|
|
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
|
|
## Solution
|
|
|
|
|
|
<section id='solution'>
|
|
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
|
// solution required
|
|
|
|
|
|
```
|
2020-08-13 17:24:35 +02:00
|
|
|
|
|
|
|
|
|
|
/section>
|
