2018-10-10 22:03:03 +00:00
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---
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id: 5900f4461000cf542c50ff58
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2020-12-16 07:37:30 +00:00
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title: 问题217:平衡数字
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2018-10-10 22:03:03 +00:00
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challengeType: 5
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videoUrl: ''
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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具有k(十进制)数字的正整数称为平衡,如果其第一个⌈k/2⌉数字总和为与其最后的⌈k/2⌉数字相同的值,其中⌈x⌉,x的发音上限,是最小整数≥x,因此⌈π⌉= 4且⌈5⌉= 5.因此,例如,所有回文都是平衡的,如13722.设T(n)是所有平衡数小于10n的总和。因此:T(1)= 45,T(2)= 540,T(5)= 334795890.求T(47)mod 315
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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`euler217()`应该返回6273134。
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert.strictEqual(euler217(), 6273134);
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2018-10-10 22:03:03 +00:00
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```
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2020-12-16 07:37:30 +00:00
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# --solutions--
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2020-08-13 15:24:35 +00:00
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