43 lines
796 B
Markdown
43 lines
796 B
Markdown
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---
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id: 5900f4f91000cf542c51000c
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title: 'Problem 397: Triangle on parabola'
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challengeType: 5
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forumTopicId: 302062
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dashedName: problem-397-triangle-on-parabola
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---
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# --description--
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On the parabola y = x2/k, three points A(a, a2/k), B(b, b2/k) and C(c, c2/k) are chosen.
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Let F(K, X) be the number of the integer quadruplets (k, a, b, c) such that at least one angle of the triangle ABC is 45-degree, with 1 ≤ k ≤ K and -X ≤ a < b < c ≤ X.
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For example, F(1, 10) = 41 and F(10, 100) = 12492. Find F(106, 109).
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# --hints--
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`euler397()` should return 141630459461893730.
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```js
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assert.strictEqual(euler397(), 141630459461893730);
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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 euler397() {
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return true;
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}
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euler397();
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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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