1.9 KiB
1.9 KiB
id | challengeType | title | forumTopicId |
---|---|---|---|
5900f36e1000cf542c50fe81 | 5 | Problem 2: Even Fibonacci Numbers | 301838 |
Description
1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
By considering the terms in the Fibonacci sequence that do not exceed the n
th term, find the sum of the even-valued terms.
Instructions
Tests
tests:
- text: <code>fiboEvenSum(10)</code> should return 44.
testString: assert.strictEqual(fiboEvenSum(10), 44);
- text: <code>fiboEvenSum(18)</code> should return 3382.
testString: assert.strictEqual(fiboEvenSum(18), 3382);
- text: <code>fiboEvenSum(23)</code> should return 60696.
testString: assert.strictEqual(fiboEvenSum(23), 60696);
- text: <code>fiboEvenSum(43)</code> should return 350704366.
testString: assert.strictEqual(fiboEvenSum(43), 350704366);
- text: Your function should return an <code>even</code> value.
testString: assert.equal(fiboEvenSum(10) % 2 === 0, true);
Challenge Seed
function fiboEvenSum(n) {
// You can do it!
return true;
}
fiboEvenSum(10);
Solution
const fiboEvenSum = (number) => {
if (number <= 1) {
return 0;
} else {
let evenSum = 2, first = 1, second = 2, fibNum; // According to problem description our Fibonacci series starts with 1, 2
for (let i = 3; i <= number; i++) {
fibNum = first + second;
first = second;
second = fibNum;
if (fibNum % 2 == 0) {
evenSum += fibNum;
}
}
return evenSum;
}
}