66 lines
1.2 KiB
Markdown
66 lines
1.2 KiB
Markdown
---
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id: 5900f5411000cf542c510053
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challengeType: 5
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title: 'Problem 469: Empty chairs'
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---
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## Description
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<section id='description'>
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In a room N chairs are placed around a round table.
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Knights enter the room one by one and choose at random an available empty chair.
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To have enough elbow room the knights always leave at least one empty chair between each other.
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When there aren't any suitable chairs left, the fraction C of empty chairs is determined.
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We also define E(N) as the expected value of C.
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We can verify that E(4) = 1/2 and E(6) = 5/9.
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Find E(1018). Give your answer rounded to fourteen decimal places in the form 0.abcdefghijklmn.
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</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>euler469()</code> should return 0.56766764161831.
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testString: assert.strictEqual(euler469(), 0.56766764161831, '<code>euler469()</code> should return 0.56766764161831.');
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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 euler469() {
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// Good luck!
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return true;
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}
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euler469();
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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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</section>
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