Nodejs Fibonacci Sequence Get sumFibs(num)

Method Source Code

Array.prototype.last = function() {
  return this[this.length-1];
};

Array.prototype.secondToLast = function() {
  return this[this.length-2];
};

function sumFibs(num) {

  var sequence = [1,1];

  while (sequence.secondToLast() + sequence.last() <= num) {
    sequence.push(sequence.secondToLast() + sequence.last());
  }/*from  www.j  a v  a2 s  .c  o m*/

  return sequence.filter(function(num) {
    return num % 2 !== 0;
  }).reduce(function(a, b) {
    return a + b;
  });
}

console.log(sumFibs(4));

Related

1. iterFib()

   Number.prototype.iterFib = function () {
     var v1 = 0, v2 = 1, temp = 0;
     (new Array()).rangeArray(0, this-1).forEach(function(index) {
       temp = v2;
       v2 = v2 + v1;
       v1 = temp;
     });
     return v2;
   

2. memoFib(hash=})

   Number.prototype.memoFib = function (hash={}) {
     if (Number(this) < 0) return -1;
     else if (Number(this) === 0) return 0;
     else if (Number(this) === 1) return 1;
     else {
       prevFib = hash[this-1] || (hash[this-1] = (this-1).memoFib(hash));
       prevPrevFib = hash[this-2] || (hash[this-2] = (this-2).memoFib(hash));
       return prevFib + prevPrevFib;
   

3. naiveFib()

   Number.prototype.naiveFib = function () {
     if (Number(this) < 0)
       return -1;
     switch (Number(this)) {
       case 0:
         return 0;
       case 1:
         return 1;
       default:
   ...