41 lines
686 B
Markdown
41 lines
686 B
Markdown
---
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id: 5900f4311000cf542c50ff44
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title: 问题197：研究递归定义的序列的行为
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challengeType: 5
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videoUrl: ''
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dashedName: problem-197-investigating-the-behaviour-of-a-recursively-defined-sequence
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---
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# --description--
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给定函数f（x）=⌊230.403243784-x2⌋×10-9（⌊⌊是floor函数），序列un由u0 = -1和un + 1 = f（un）定义。
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找到n + 1012的un + un + 1.在小数点后面给出9位数的答案。
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# --hints--
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`euler197()`应该返回1.710637717。
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```js
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assert.strictEqual(euler197(), 1.710637717);
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```
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# --seed--
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## --seed-contents--
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```js
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function euler197() {
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return true;
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}
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euler197();
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```
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# --solutions--
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```js
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// solution required
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```
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