freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-254-sums-of-digit-f...

68 lines
1.2 KiB
Markdown
Raw Normal View History

---
id: 5900f46b1000cf542c50ff7d
challengeType: 5
title: 'Problem 254: Sums of Digit Factorials'
forumTopicId: 301902
---
## Description
<section id='description'>
Define f(n) as the sum of the factorials of the digits of n. For example, f(342) = 3! + 4! + 2! = 32.
Define sf(n) as the sum of the digits of f(n). So sf(342) = 3 + 2 = 5.
Define g(i) to be the smallest positive integer n such that sf(n) = i. Though sf(342) is 5, sf(25) is also 5, and it can be verified that g(5) is 25.
Define sg(i) as the sum of the digits of g(i). So sg(5) = 2 + 5 = 7.
Further, it can be verified that g(20) is 267 and ∑sg(i) for 1 ≤ i ≤ 20 is 156.
What is ∑sg(i) for 1 ≤ i ≤ 150?
</section>
## Instructions
<section id='instructions'>
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: <code>euler254()</code> should return 8184523820510.
testString: assert.strictEqual(euler254(), 8184523820510);
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
function euler254() {
return true;
}
euler254();
```
</div>
</section>
## Solution
<section id='solution'>
```js
// solution required
```
</section>