56 lines
1.6 KiB
Markdown
56 lines
1.6 KiB
Markdown
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---
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id: 5900f4091000cf542c50ff1b
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challengeType: 5
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title: 'Problem 156: Counting Digits'
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videoUrl: ''
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localeTitle: ''
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---
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## Description
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<section id="description">从零开始,自然数字在基数10中写下,如下所示: <p> 0 1 2 3 4 5 6 7 8 9 10 11 12 .... </p><p>考虑数字d = 1。在我们写下每个数字n后,我们将更新已发生的数字并将此数字称为f(n,1)。那么f(n,1)的第一个值如下: </p><p> nf(n,1)00 11 21 31 41 51 61 71 81 91 102 114 125 </p><p>请注意,f(n,1)永远不等于3。 </p><p>因此,等式f(n,1)= n的前两个解是n = 0并且n = 1。下一个解决方案是n = 199981。以相同的方式,函数f(n,d)给出在写入数字n之后已经写下的总位数d。 </p><p>实际上,对于每个数字d≠0,0是方程f(n,d)= n的第一个解。设s(d)是f(n,d)= n的所有解的总和。 </p><p>你得到s(1)= 22786974071。找到Σs(d)的1≤d≤9。注意:如果对于某些n,对于多于一个d的值,f(n,d)= n,对于d的每个值,再次计算n的这个值。 F(N,d)= N。 </p></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: ''
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testString: 'assert.strictEqual(euler156(), 21295121502550, "<code>euler156()</code> should return 21295121502550.");'
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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 euler156() {
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// Good luck!
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return true;
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}
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euler156();
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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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