2018-10-10 22:03:03 +00:00
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---
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id: 5900f4f71000cf542c510009
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challengeType: 5
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videoUrl: ''
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2020-10-01 15:54:21 +00:00
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title: 问题394:吃馅饼
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2018-10-10 22:03:03 +00:00
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---
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## Description
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<section id="description">杰夫以一种不同寻常的方式吃馅饼。馅饼是圆形的。他首先沿着半径切割馅饼中的初始切口。虽然剩下至少给定的馅饼F分数,但他执行以下程序: - 他从饼图中心到馅饼边框剩余的任何一点做两个切片,剩下的馅饼边框上的任何一点都有可能。这将把剩下的馅饼分成三块。 - 从最初的切割逆时针走,他拿出前两个馅饼并吃掉它们。当剩下不到一小部分馅饼时,他不再重复这个过程。相反,他吃剩下的所有馅饼。 <p>对于x≥1,设E(x)是Jeff重复上述过程的预期次数,F = 1 / x。可以证实E(1)= 1,E(2)≈1.2676536759,和E(7.5)≈2.1215732071。 </p><p>找到E(40)舍入到小数点后面的10位小数。 </p></section>
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## Instructions
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<section id="instructions">
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>euler394()</code>应返回3.2370342194。
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2020-02-17 16:40:55 +00:00
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testString: assert.strictEqual(euler394(), 3.2370342194);
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2018-10-10 22:03:03 +00:00
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function euler394() {
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// Good luck!
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return true;
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}
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euler394();
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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2020-08-13 15:24:35 +00:00
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/section>
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