Sword_Offer 斐波拉契数列[10]

Sword_Offer 斐波拉契数列[10]

题目一：求斐波拉契数列的第n项

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# Author LQ6H

class Solution:
    def Fibonacci(self,n):
        if n<=0:
            return 0

        if n==1:
            return 1

        return self.Fibonacci(n-1)+self.Fibonacci(n-2)

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# Author LQ6H

class Solution:
    def Fibonacci(self,n):

        result=[0,1]

        if n<2:
            return result[n]

        fibMinusOne=1
        fibMinusTwo=0
        fibSum=0

        for i in range(2,n+1):
            fibSum=fibMinusOne+fibMinusTwo
            fibMinusTwo=fibMinusOne
            fibMinusOne=fibSum

        return fibSum

题目二：青蛙跳台阶

0x00 题目描述

题目：一次可以跳上1级台阶,也可以跳上2级台阶.求跳上一个n级台阶共有多少种调法

f(n)=f(n-1)+f(n-2)

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# Author LQ6H

class Solution:
    def Fibonacci(self,n):
        if n<=3:
            return n

        return self.Fibonacci(n-1)+self.Fibonacci(n-2)