题解 | #斐波那契数列#

#用递归会方便一点,这写法太cao了，三个变量轮流存
class Solution:
    def Fibonacci(self , n: int) -> int:
        # write code here
        f1,f2,sun=1,1,0
        if n==0:
            return 0
        if n<=2:
            return f1
        for i in range(n-2):
            sun=f1+f2
            f1=f2
            f2=sun
        return sun
num=int(input())
s=Solution()
print(s.Fibonacci(num))