79d9012432
* fix(curriculum): tests quotes * fix(curriculum): fill seed-teardown * fix(curriculum): fix tests and remove unneeded seed-teardown
67 lines
1007 B
Markdown
67 lines
1007 B
Markdown
---
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id: 5900f4ea1000cf542c50fffc
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challengeType: 5
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title: 'Problem 381: (prime-k) factorial'
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---
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## Description
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<section id='description'>
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For a prime p let S(p) = (∑(p-k)!) mod(p) for 1 ≤ k ≤ 5.
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For example, if p=7,
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(7-1)! + (7-2)! + (7-3)! + (7-4)! + (7-5)! = 6! + 5! + 4! + 3! + 2! = 720+120+24+6+2 = 872.
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As 872 mod(7) = 4, S(7) = 4.
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It can be verified that ∑S(p) = 480 for 5 ≤ p < 100.
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Find ∑S(p) for 5 ≤ p < 108.
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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>euler381()</code> should return 139602943319822.
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testString: assert.strictEqual(euler381(), 139602943319822, '<code>euler381()</code> should return 139602943319822.');
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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 euler381() {
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// Good luck!
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return true;
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}
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euler381();
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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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