2018-09-30 22:01:58 +00:00
|
|
|
---
|
|
|
|
id: 5900f36e1000cf542c50fe81
|
|
|
|
challengeType: 5
|
|
|
|
title: 'Problem 2: Even Fibonacci Numbers'
|
|
|
|
---
|
|
|
|
|
|
|
|
## Description
|
|
|
|
<section id='description'>
|
|
|
|
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
|
|
|
|
<div style='text-align: center;'>1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...</div>
|
|
|
|
By considering the terms in the Fibonacci sequence whose values do not exceed <code>n</code>th term, find the sum of the even-valued terms.
|
|
|
|
</section>
|
|
|
|
|
|
|
|
## Instructions
|
|
|
|
<section id='instructions'>
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
## Tests
|
|
|
|
<section id='tests'>
|
|
|
|
|
|
|
|
```yml
|
2018-10-04 13:37:37 +00:00
|
|
|
tests:
|
|
|
|
- text: <code>fiboEvenSum(10)</code> should return 188.
|
2018-10-20 18:02:47 +00:00
|
|
|
testString: assert.strictEqual(fiboEvenSum(10), 188, '<code>fiboEvenSum(10)</code> should return 188.');
|
2018-10-04 13:37:37 +00:00
|
|
|
- text: <code>fiboEvenSum(23)</code> should return 60696.
|
2018-10-20 18:02:47 +00:00
|
|
|
testString: assert.strictEqual(fiboEvenSum(23), 60696, '<code>fiboEvenSum(23)</code> should return 60696.');
|
2018-10-04 13:37:37 +00:00
|
|
|
- text: <code>fiboEvenSum(43)</code> should return 1485607536.
|
2018-10-20 18:02:47 +00:00
|
|
|
testString: assert.strictEqual(fiboEvenSum(43), 1485607536, '<code>fiboEvenSum(43)</code> should return 1485607536.');
|
2018-10-04 13:37:37 +00:00
|
|
|
- text: Your function is not returning the correct result using our tests values.
|
2018-10-20 18:02:47 +00:00
|
|
|
testString: assert.strictEqual(fiboEvenSum(18), 3382, 'Your function is not returning the correct result using our tests values.');
|
2018-10-04 13:37:37 +00:00
|
|
|
- text: Your function should return an <code>even</code> value.
|
2018-10-20 18:02:47 +00:00
|
|
|
testString: assert.equal(fiboEvenSum(31) % 2 === 0, true, 'Your function should return an <code>even</code> value.');
|
2018-09-30 22:01:58 +00:00
|
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
## Challenge Seed
|
|
|
|
<section id='challengeSeed'>
|
|
|
|
|
|
|
|
<div id='js-seed'>
|
|
|
|
|
|
|
|
```js
|
|
|
|
function fiboEvenSum(n) {
|
|
|
|
// You can do it!
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
fiboEvenSum(10);
|
|
|
|
```
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
## Solution
|
|
|
|
<section id='solution'>
|
|
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
const fiboEvenSum = (number) => {
|
|
|
|
let temp, sum = 0, a = 0, b = 1;
|
|
|
|
while (number >= 0) {
|
|
|
|
temp = a;
|
|
|
|
a = b;
|
|
|
|
b += temp;
|
|
|
|
number --;
|
|
|
|
if ((b % 2) === 0) {
|
|
|
|
sum += b;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return sum;
|
|
|
|
}
|
|
|
|
```
|
|
|
|
|
|
|
|
</section>
|