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
1.1 KiB
Markdown
53 lines
1.1 KiB
Markdown
---
|
||
id: 5900f3b41000cf542c50fec7
|
||
title: 关卡 72：分数计数
|
||
challengeType: 5
|
||
forumTopicId: 302185
|
||
dashedName: problem-72-counting-fractions
|
||
---
|
||
|
||
# --description--
|
||
|
||
考虑形如 `n`/`d` 的分数，其中 n 和 d 均为正整数。如果 `n`<`d`，且最大公约数 HCF(`n`,`d`)=1，则该分数被称为最简真分数。
|
||
|
||
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：
|
||
|
||
<div style='text-align: center;'>1/8, 1/7, 1/6, 1/5, 1/4, 2/7, 1/3, 3/8, 2/5, 3/7, 1/2, 4/7, 3/5, 5/8, 2/3, 5/7, 3/4, 4/5, 5/6, 6/7, 7/8</div>
|
||
|
||
可以看出该集合中共有 21 个元素。
|
||
|
||
求 `d` ≤ 1,000,000 的最简真分数构成的集合中共有多少个元素。
|
||
|
||
# --hints--
|
||
|
||
`countingFractions()` 应该返回一个数字。
|
||
|
||
```js
|
||
assert(typeof countingFractions() === 'number');
|
||
```
|
||
|
||
`countingFractions()` 应该返回 303963552391。
|
||
|
||
```js
|
||
assert.strictEqual(countingFractions(), 303963552391);
|
||
```
|
||
|
||
# --seed--
|
||
|
||
## --seed-contents--
|
||
|
||
```js
|
||
function countingFractions() {
|
||
|
||
return true;
|
||
}
|
||
|
||
countingFractions();
|
||
```
|
||
|
||
# --solutions--
|
||
|
||
```js
|
||
// solution required
|
||
```
|