1 #include <iostream>
 2 using namespace std;
 3 class Solution {
 4 public:
 5     //fn=f(n-1)+f(n-2)
 6     //f1=1   f2=2
 7     int jumpFloor(int number) {
 8         int result[3]={0,1,2};
 9         int f1=1;
10         int f2=2;
11         int fn = 0;
12         if(number<=2)
13             return result[number];
14         else
15         {
16             for(int i=3;i<=number;i++)
17             {
18                 fn = f1 + f2;
19                 f1 = f2;
20                 f2 = fn;
21             }
22         }
23         return fn;
24     }
25 };
26 int main()
27 {
28     int n;
29     while(cin>>n)
30     {
31         Solution s;
32         cout<<"跳"<<n<<"级台阶需要步数："<<s.jumpFloor(n)<<endl;
33     }
34     return 0;
35 }