69 lines
1.1 KiB
Markdown
69 lines
1.1 KiB
Markdown
---
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id: 5900f49d1000cf542c50ffb0
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challengeType: 5
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videoUrl: ''
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title: 问题305：反身姿势
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---
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## Description
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<section id="description">
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我们称S为（无限）字符串，该字符串是通过连接以10为底的连续正整数（从1开始）而形成的。
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因此，S = 1234567891011121314151617181920212223242 ...
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很容易看出，任何数字在S中都会显示无数次。
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让我们将f（n）称为S中第n次出现n的起始位置。
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例如，f（1）= 1，f（5）= 81，f（12）= 271和f（7780）= 111111365。
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求出∑f（3k）为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>应该返回18174995535140。
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testString: assert.strictEqual(euler305(), 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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