【算法編程】青蛙跳臺階

題目來源：牛客網劍指offer

題目描述：一隻青蛙一次能夠跳上1級臺階，也能夠跳上2級。求該青蛙跳上一個n級的臺階總共有多少種跳法。

解題思路：f(n) = f(n-1) + f(n-2)

C++: 3ms 492k

#include <iostream>
using namespace std; class Solution { public: int jumpFloor(int number) { int jump0 = 1; int jump1 = 1; while(number-->1){ jump1 += jump0; jump0 = jump1 - jump0; } return jump1; } }; int main() { Solution obj; int n; while(cin>>n){ cout<<obj.jumpFloor(n)<<endl; } cin.get(); cin.get(); }

Python: 30ms 5732k

# -*- coding:utf-8 -*-
import sys class Solution: def jumpFloor(self, number): # f(n) = f(n-1) + f(n-2)
        jump0 = 1 # two steps: 1,1;2 jump0+jump1
        jump1 = 1 # one step: 1
        while (number>1): jump1 += jump0 jump0 = jump1 - jump0 number -= 1
        return jump1 if __name__ == '__main__': obj = Solution() while (1): x = input() print obj.jumpFloor(x)