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>
39 lines
1.1 KiB
Markdown
39 lines
1.1 KiB
Markdown
---
|
||
id: 5900f3b61000cf542c50fec9
|
||
title: 问题74：数字因子链
|
||
challengeType: 5
|
||
videoUrl: ''
|
||
dashedName: problem-74-digit-factorial-chains
|
||
---
|
||
|
||
# --description--
|
||
|
||
数字145是众所周知的，其数字的阶乘之和等于145：1！ + 4！ + 5！ = 1 + 24 + 120 = 145也许知名度较低的是169，因为它产生了最长的数字链，可以链接到169;事实证明，只存在三个这样的循环：169→363601→1454→169 871→45361→871 872→45362→872不难证明每个起始编号最终都会陷入循环。例如，69→363600→1454→169→363601（→1454）78→45360→871→45361（→871）540→145（→145）从69开始产生五个非重复项链，但最长起始数低于一百万的非重复链是60个项。起始数低于一百万的链中有多少个包含正好六十个非重复项？
|
||
|
||
# --hints--
|
||
|
||
`euler74()`应返回402。
|
||
|
||
```js
|
||
assert.strictEqual(euler74(), 402);
|
||
```
|
||
|
||
# --seed--
|
||
|
||
## --seed-contents--
|
||
|
||
```js
|
||
function digitFactorialChains() {
|
||
|
||
return true;
|
||
}
|
||
|
||
digitFactorialChains();
|
||
```
|
||
|
||
# --solutions--
|
||
|
||
```js
|
||
// solution required
|
||
```
|