2018-10-10 18:03:03 -04:00
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---
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id: 5900f5001000cf542c510013
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2020-12-16 00:37:30 -07:00
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title: 问题403:由抛物线和直线包围的格点
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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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2021-01-13 03:31:00 +01:00
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dashedName: problem-403-lattice-points-enclosed-by-parabola-and-line
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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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# --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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对于整数a和b,我们将D(a,b)定义为由抛物线y = x2包围的域,并且线y = a·x + b:D(a,b)= {(x,y)| x2≤y≤a·x + b}。
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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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L(a,b)定义为D(a,b)中包含的晶格点数。例如,L(1,2)= 8并且L(2,-1)= 1。
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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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我们还将S(N)定义为所有对(a,b)的L(a,b)之和,使得D(a,b)的面积是有理数并且| a |,| b | ≤N。我们可以验证S(5)= 344和S(100)= 26709528。
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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S(1012)。给你的答案mod 108。
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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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`euler403()`应该返回18224771。
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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(euler403(), 18224771);
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2018-10-10 18:03:03 -04:00
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```
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2021-01-13 03:31:00 +01:00
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# --seed--
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## --seed-contents--
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```js
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function euler403() {
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return true;
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}
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euler403();
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```
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2020-12-16 00:37:30 -07:00
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# --solutions--
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2020-08-13 17:24:35 +02:00
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2021-01-13 03:31:00 +01:00
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```js
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// solution required
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```
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