fibonacci_sequence.py

# Hi, here's your problem today. This problem was recently asked by Apple:
#
# The Fibonacci sequence is the integer sequence defined by the recurrence relation: F(n) = F(n-1) + F(n-2), where F(0) = 0 and F(1) = 1. In other words, the nth Fibonacci number is the sum of the prior two Fibonacci numbers. Below are the first few values of the sequence:
#
# 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144...
#
# Given a number n, print the n-th Fibonacci Number.
# Examples:
# Input: n = 3
# Output: 2
#
# Input: n = 7
# Output: 13
# Here's a starting point:
#
# class Solution():
#   def fibonacci(self, n):
#     # fill this in.
#
# n = 9
# print(Solution().fibonacci(n))
# 34

class solution():
    def fibonacci(self, n):
        signature = [0, 1]
        signature = signature[:n]
        for i in range(n-1):
            signature.append(sum(signature[-2:]))
        if len(signature) != 0:
            return signature[-1]
        else:
            return

n = 3
print(solution().fibonacci(n))