Files
OI-source/history_source/信息学奥赛一本通/1.4.4.2.cpp
2023-08-03 09:22:52 +08:00

18 lines
211 B
C++

#include<cstdio>
using namespace std;
int main()
{
int n;
long long times=1;
double ans=0;
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
times*=i;
ans+=1.0/times;
}
printf("%.10lf\n",ans+1);
return 0;
}