We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. All Contests
  2. ProjectEuler+
  3. Project Euler #25: N-digit Fibonacci number
  4. Discussions

Project Euler #25: N-digit Fibonacci number

Sort 76 Discussions, By:

  • jklebes
     + 0 comments

    For those whose test case 3 is failing despite using the formula, "Wrong Answer" not Timeout, increase precision from float to double.

  • varresumanchait1
     + 1 comment
    from math import log10 as log
from math import sqrt
def num_of_digits(n):
    if n == 1:
        return 1
    a = log((1 + sqrt(5))/2)
    b = ((log(5)) / 2)
    return(int((n+b-1)/a) + 1)
# print(num_of_digits(5))
T = int(input())
for a0 in range(T):
    N = int(input())
    print(num_of_digits(N))

  • mdasif9a
     + 0 comments

    This Will Help You

    from math import log10, ceil, sqrt
phi = (1+sqrt(5))/2 #phi is the golden ratio
t = int(input())
for a0 in range(t):
    d = int(input())
    term = ceil((log10(5)/2+d-1)/ log10(phi))
    print(term)

  • v33vikasgautam
     + 0 comments

    here is a true O(1) solution. No dp, no loops nothing, Just reverse engineering.

    ; Takes the length of fib return the (index of fib) + 1
(defn fib-len-rev [l]
  (let [phi (-> (Math/sqrt 5) (+ 1) (/ 2))]
  (-> (+ (dec l)
         (* 1/2 (Math/log10 5)))
      (/ (Math/log10 phi))
      (Math/ceil)
      (int))))

  • VamshiKancharla
     + 0 comments

    Hey Folks, 

        Do you know if there was any change in the rules of Euler competition ? I am not able to view & download the testcases. 

            I was able to View & Download the test Cases by using hackos before. 

            Please let me know.

    Thanks, Vamshi.

Load more conversations