用python写算法4[Fibnocci数列的两种实现]

题目: 实现递归和非递归实现Fibonacci数列

解答:

#!/usr/bin/python

def Fibonacci(n):
    a = [0, 1]
    if n < 2:    return a[n]

    fibNMinusOne = 1
    fibNMinusTwo = 0

    for n in range(2,n+1):
        fibN = fibNMinusTwo + fibNMinusOne

        fibNMinusTwo = fibNMinusOne
        fibNMinusOne = fibN

    return fibN    

def Fibonacci1(n):
    if n <= 0:
        return 0

    if n == 1:
        return 1

    return Fibonacci1(n-1) + Fibonacci1(n-2)

def main():
    print Fibonacci(10)
    
    print Fibonacci1(10)

if __name__ == '__main__':
    main()