2018-10-10 22:03:03 +00:00
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---
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id: 5900f5151000cf542c510028
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challengeType: 5
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videoUrl: ''
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2020-10-01 15:54:21 +00:00
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title: 问题425:主要连接
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2018-10-10 22:03:03 +00:00
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---
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## Description
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2020-02-17 16:40:55 +00:00
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<section id="description">
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如果满足以下条件之一,则称两个正数A和B被连接(用“ A↔B”表示):
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(1)A和B的长度相同,且仅相差一位数; 例如123↔173。
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(2)在A(或B)的左边加一位使B(或A)成为数字; 例如23↔223和123↔23。
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如果在2和P之间存在连接的素数链,并且链中没有素数超过P,则我们称素数为P a 2的相对数。
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例如,127是2的亲戚。 可能的链之一如下所示:
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2分3分13分113分103分107分127
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但是,11和103不是2的亲戚。
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令F(N)为素数≤N的和,它们不是2的相对数。
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我们可以验证F(103)= 431和F(104)= 78728。
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找出F(107)。
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</section>
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2018-10-10 22:03:03 +00:00
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## Instructions
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2020-02-17 16:40:55 +00:00
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<section id="instructions">
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</section>
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2018-10-10 22:03:03 +00:00
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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>euler425()</code>应该返回46479497324。
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2020-02-17 16:40:55 +00:00
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testString: assert.strictEqual(euler425(), 46479497324);
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2018-10-10 22:03:03 +00:00
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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 euler425() {
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// Good luck!
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return true;
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}
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euler425();
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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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2020-08-13 15:24:35 +00:00
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/section>
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