63 lines
1018 B
Markdown
63 lines
1018 B
Markdown
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---
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id: 5900f43e1000cf542c50ff50
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challengeType: 5
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title: 'Problem 210: Obtuse Angled Triangles'
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forumTopicId: 301852
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---
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## Description
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<section id='description'>
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Consider the set S(r) of points (x,y) with integer coordinates satisfying |x| + |y| ≤ r.
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Let O be the point (0,0) and C the point (r/4,r/4).
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Let N(r) be the number of points B in S(r), so that the triangle OBC has an obtuse angle, i.e. the largest angle α satisfies 90°<α<180°.
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So, for example, N(4)=24 and N(8)=100.
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What is N(1,000,000,000)?
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>euler210()</code> should return 1598174770174689500.
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testString: assert.strictEqual(euler210(), 1598174770174689500);
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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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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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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