```
#include<bits/stdc++.h>
using namespace std;
double c[100000];
double f(long long x){
if(x==0) return 0;
if(x==1||x==2) return 1;
if(c[x]>0) return c[x];
double a=f(x-1)+f(x-2);
c[x]=a;
return a;
}
int main(){
long long m;
cin>>m;
printf("%.2f",(double)f(m));
return 0;
}
```
by drinktowind @ 2023-09-28 20:42:10
改了一下，精度有问题&初始值赋错了
by drinktowind @ 2023-09-28 20:43:02
求关QwQ
by drinktowind @ 2023-09-28 20:43:38
@[drinktowind](/user/719619)
谢谢
by Ac_Code_cn_com @ 2023-09-28 20:47:20