$$F_n=\dfrac{\left(\frac{1+\sqrt{5}}{2}\right)^n-\left(\frac{1-\sqrt{5}}{2}\right)^n}{\sqrt{5}}$$
请按公式计算！
```cpp
#include<bits/stdc++.h>
double n,o=sqrt(5),a=1,b=1,i;
int main(){
for(scanf("%lf",&n),i=1;i<=n;++i)a*=(1+o)/2,b*=(1-o)/2;
return printf("%.2lf",(a-b)/o),0;
}
```
by xiaoyuhao0503 @ 2024-02-16 19:10:29
@[xiaoyuhao0503](/user/1238473) 感谢
by lyy_zy @ 2024-02-19 21:51:32
这是普通的斐波那契吗？ 小学生，看不懂一点
by LiXiang190208 @ 2024-04-20 19:58:03