-
Notifications
You must be signed in to change notification settings - Fork 0
/
P2.js
61 lines (51 loc) · 1.56 KB
/
P2.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
/* ====== Problem 2 =================================== *
*
* 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:
*
* 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
*
* By considering the terms in the Fibonacci sequence whose values
* do not exceed four million, find the sum of the even-valued terms.
*
* ========================================**/
const MAX_VALUE = 4e6;
function fibonacciSequence(x, container) {
// base case, if value exceeds 4e6
if (nextValue(x) > MAX_VALUE)
return;
// recursive case:
container.push(nextValue(x));
fibonacciSequence(container.slice(-2, container.length), container);
// return value
return container;
}
function nextValue(x) {
return x[0] + x[1];
}
function sumEvenValues(valueArray) {
return valueArray.filter(function(a){
return a % 2 === 0;
}).reduce(function(a, b) {
return a + b;
}, 0);
}
function solution() {
var value = fibonacciSequence([1, 2], [1, 2]);
var answer = sumEvenValues(value);
console.log(`The sum of all even numbers in the Fibonacci sequence
under four million is: ${answer}`);
}
solution();
/* ====== Meta ========================================= *
*
* Estimated time of completion: 25 minutes
* Search engine used: no
* Concepts learned: sequences
*
* Additional notes: Not a very general way to do this.
* Ideally would not have the base case in the function
* parameters. Think of a way to make this cleaner.
*
* ========================================**/