79d9012432
* fix(curriculum): tests quotes * fix(curriculum): fill seed-teardown * fix(curriculum): fix tests and remove unneeded seed-teardown
67 lines
1.1 KiB
Markdown
67 lines
1.1 KiB
Markdown
---
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id: 5900f49d1000cf542c50ffb0
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challengeType: 5
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title: 'Problem 305: Reflexive Position'
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---
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## Description
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<section id='description'>
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Let's call S the (infinite) string that is made by concatenating the consecutive positive integers (starting from 1) written down in base 10.
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Thus, S = 1234567891011121314151617181920212223242...
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It's easy to see that any number will show up an infinite number of times in S.
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Let's call f(n) the starting position of the nth occurrence of n in S.
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For example, f(1)=1, f(5)=81, f(12)=271 and f(7780)=111111365.
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Find ∑f(3k) for 1≤k≤13.
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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>euler305()</code> should return 18174995535140.
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testString: assert.strictEqual(euler305(), 18174995535140, '<code>euler305()</code> should return 18174995535140.');
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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 euler305() {
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// Good luck!
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return true;
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}
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euler305();
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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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