63 lines
1.6 KiB
Markdown
63 lines
1.6 KiB
Markdown
---
|
||
title: Evaluate binomial coefficients
|
||
id: 598de241872ef8353c58a7a2
|
||
challengeType: 5
|
||
videoUrl: ''
|
||
localeTitle: 评估二项式系数
|
||
---
|
||
|
||
## Description
|
||
<section id="description"><p>写一个函数来计算给定n和k值的二项式系数。 </p><p>推荐这个公式: </p> $ \ binom {n} {k} = \ frac {n!} {(nk)!k!} = \ frac {n(n-1)(n-2)\ ldots(n-k + 1)} { k(k-1)(k-2)\ ldots 1} $ </section>
|
||
|
||
## Instructions
|
||
<section id="instructions">
|
||
</section>
|
||
|
||
## Tests
|
||
<section id='tests'>
|
||
|
||
```yml
|
||
tests:
|
||
- text: <code>binom</code>是一个功能。
|
||
testString: 'assert(typeof binom === "function", "<code>binom</code> is a function.");'
|
||
- text: '<code>binom(5,3)</code>应该返回10。'
|
||
testString: 'assert.equal(binom(5, 3), 10, "<code>binom(5,3)</code> should return 10.");'
|
||
- text: '<code>binom(7,2)</code>应该返回21。'
|
||
testString: 'assert.equal(binom(7, 2), 21, "<code>binom(7,2)</code> should return 21.");'
|
||
- text: '<code>binom(10,4)</code>应该返回210。'
|
||
testString: 'assert.equal(binom(10, 4), 210, "<code>binom(10,4)</code> should return 210.");'
|
||
- text: '<code>binom(6,1)</code>应该返回6。'
|
||
testString: 'assert.equal(binom(6, 1), 6, "<code>binom(6,1)</code> should return 6.");'
|
||
- text: '<code>binom(12,8)</code>应该返回495。'
|
||
testString: 'assert.equal(binom(12, 8), 495, "<code>binom(12,8)</code> should return 495.");'
|
||
|
||
```
|
||
|
||
</section>
|
||
|
||
## Challenge Seed
|
||
<section id='challengeSeed'>
|
||
|
||
<div id='js-seed'>
|
||
|
||
```js
|
||
function binom (n, k) {
|
||
// Good luck!
|
||
}
|
||
|
||
```
|
||
|
||
</div>
|
||
|
||
|
||
|
||
</section>
|
||
|
||
## Solution
|
||
<section id='solution'>
|
||
|
||
```js
|
||
// solution required
|
||
```
|
||
</section>
|