2018-10-10 18:03:03 -04:00
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---
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id: 5900f4491000cf542c50ff5c
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2020-12-16 00:37:30 -07:00
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title: 问题221:亚历山大整数
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2018-10-10 18:03:03 -04:00
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challengeType: 5
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videoUrl: ''
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---
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2020-12-16 00:37:30 -07:00
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# --description--
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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如果存在整数p,q,r,我们将调用正整数A和“亚历山大整数”,这样:
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```
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A = p · q · r and 1A
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2018-10-10 18:03:03 -04:00
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```
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2020-12-16 00:37:30 -07:00
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=
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```
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1p
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```
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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\+
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```
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1q
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```
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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\+
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```
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1r
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2018-10-10 18:03:03 -04:00
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```
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2020-12-16 00:37:30 -07:00
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例如,630是亚历山大整数(p = 5,q = -7,r = -18)。实际上,630是第6个亚历山大整数,前6个亚历山大整数是:6,42,120,156,420和630。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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找到第150000个亚历山大整数。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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# --hints--
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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`euler221()`应该返回1884161251122450。
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2018-10-10 18:03:03 -04:00
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```js
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2020-12-16 00:37:30 -07:00
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assert.strictEqual(euler221(), 1884161251122450);
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2018-10-10 18:03:03 -04:00
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```
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2020-08-13 17:24:35 +02:00
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2020-12-16 00:37:30 -07:00
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# --solutions--
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