2018-10-10 22:03:03 +00:00
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---
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id: 5900f43e1000cf542c50ff50
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2020-12-16 07:37:30 +00:00
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title: 问题210:钝角三角形
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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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2021-01-13 02:31:00 +00:00
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dashedName: problem-210-obtuse-angled-triangles
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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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# --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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考虑点(x,y)的集合S(r),其中整数坐标满足| x | + | y | ≤r。设O为点(0,0),C为点(r / 4,r / 4)。令N(r)为S(r)中的点B的数量,使得三角形OBC具有钝角,即最大角度α满足90°<α<180°。因此,例如,N(4)= 24并且N(8)= 100。
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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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什么是N(1,000,000,000)?
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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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`euler210()`应该返回1598174770174689500。
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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(euler210(), 1598174770174689500);
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2018-10-10 22:03:03 +00:00
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```
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2021-01-13 02:31:00 +00:00
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# --seed--
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## --seed-contents--
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```js
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function euler210() {
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return true;
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}
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euler210();
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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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2021-01-13 02:31:00 +00:00
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```js
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// solution required
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```
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