ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
53 lines
1.2 KiB
Markdown
53 lines
1.2 KiB
Markdown
---
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id: 5900f3b61000cf542c50fec8
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title: 关卡 73：区间内的分数个数
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challengeType: 5
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forumTopicId: 302186
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dashedName: problem-73-counting-fractions-in-a-range
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---
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# --description--
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考虑形如 `n`/`d` 的分数，其中 n 和 d 均为正整数。如果 `n`<`d`，且其最大公约数 HCF(`n`,`d`)=1，则该分数被称为最简真分数。
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如果我们将 `d` ≤ 8 的最简真分数构成的集合按大小升序列出，将得到：
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<div style='text-align: center;'>1/8, 1/7, 1/6, 1/5, 1/4, 2/7, 1/3, <strong>3/8</strong>, <strong>2/5</strong>, <strong>3/7</strong>, 1/2, 4/7, 3/5, 5/8, 2/3, 5/7, 3/4, 4/5, 5/6, 6/7, 7/8</div>
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可以看出在 1/3 和 1/2 之间有3个分数。
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将 `d` ≤ 12,000 的最简真分数构成的集合排序后，在 1/3 和 1/2 之间有多少个分数？
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# --hints--
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`countingFractionsInARange()` 应该返回一个数字。
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```js
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assert(typeof countingFractionsInARange() === 'number');
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```
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`countingFractionsInARange()` 应该返回 7295372。
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```js
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assert.strictEqual(countingFractionsInARange(), 7295372);
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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 countingFractionsInARange() {
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return true;
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}
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countingFractionsInARange();
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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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