【算法编程】青蛙跳台阶

题目来源：牛客网剑指offer

题目描述：一只青蛙一次可以跳上1级台阶，也可以跳上2级。求该青蛙跳上一个n级的台阶总共有多少种跳法。

解题思路：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)