68 lines
1.1 KiB
Markdown
68 lines
1.1 KiB
Markdown
---
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id: 5900f4ef1000cf542c510001
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challengeType: 5
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title: 'Problem 386: Maximum length of an antichain'
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forumTopicId: 302050
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---
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## Description
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<section id='description'>
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Let n be an integer and S(n) be the set of factors of n.
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A subset A of S(n) is called an antichain of S(n) if A contains only one element or if none of the elements of A divides any of the other elements of A.
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For example: S(30) = {1, 2, 3, 5, 6, 10, 15, 30}
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{2, 5, 6} is not an antichain of S(30).
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{2, 3, 5} is an antichain of S(30).
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Let N(n) be the maximum length of an antichain of S(n).
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Find ΣN(n) for 1 ≤ n ≤ 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>euler386()</code> should return 528755790.
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testString: assert.strictEqual(euler386(), 528755790);
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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 euler386() {
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// Good luck!
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return true;
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}
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euler386();
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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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