64 lines
1.0 KiB
Markdown
64 lines
1.0 KiB
Markdown
---
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id: 5900f5331000cf542c510046
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challengeType: 5
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title: 'Problem 455: Powers With Trailing Digits'
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---
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## Description
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<section id='description'>
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Let f(n) be the largest positive integer x less than 109 such that the last 9 digits of nx form the number x (including leading zeros), or zero if no such integer exists.
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For example:
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f(4) = 411728896 (4411728896 = ...490411728896)
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f(10) = 0
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f(157) = 743757 (157743757 = ...567000743757)
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Σf(n), 2 ≤ n ≤ 103 = 442530011399
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Find Σf(n), 2 ≤ n ≤ 106.
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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>euler455()</code> should return 450186511399999.
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testString: assert.strictEqual(euler455(), 450186511399999, '<code>euler455()</code> should return 450186511399999.');
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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 euler455() {
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// Good luck!
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return true;
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}
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euler455();
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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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