Instructions

The Fibonacci numbers are the numbers in the following integer sequence (Fn):

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, ...

such as

F(n) = F(n-1) + F(n-2) with F(0) = 0 and F(1) = 1.

Given a number, say prod (for product), we search two Fibonacci numbers F(n) and F(n+1) verifying

F(n) * F(n+1) = prod.

Your function productFib takes an integer (prod) and returns an array:

[F(n), F(n+1), true] or {F(n), F(n+1), 1} or (F(n), F(n+1), True)

depending on the language if F(n) * F(n+1) = prod.

If you don't find two consecutive F(n) verifying F(n) * F(n+1) = prodyou will return

[F(n), F(n+1), false] or {F(n), F(n+1), 0} or (F(n), F(n+1), False)

F(n) being the smallest one such as F(n) * F(n+1) > prod.

Some Examples of Return:

(depend on the language)

productFib(714) # should return (21, 34, true), 
                # since F(8) = 21, F(9) = 34 and 714 = 21 * 34

productFib(800) # should return (34, 55, false), 
                # since F(8) = 21, F(9) = 34, F(10) = 55 and 21 * 34 < 800 < 34 * 55
-----
productFib(714) # should return [21, 34, true], 
productFib(800) # should return [34, 55, false], 
-----
productFib(714) # should return {21, 34, 1}, 
productFib(800) # should return {34, 55, 0},        
-----
productFib(714) # should return {21, 34, true}, 
productFib(800) # should return {34, 55, false},

Note:

• You can see examples for your language in "Sample Tests".

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My solution

export const productFib = (prod:number): [number,number,boolean] => {
  let front = 0,
      back = 1
  while (front * back < prod) {
    back += front
    front = back - front
  }
  return [front, back, front * back === prod]
}

Please check this problem at this Link!