```cpp
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<sstream>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
#include<iomanip>
#include<time.h>
using namespace std;
int main()
{
double a,p=3.141592653589783238462643383279;
cin>>a;
printf("%.6llf\n%.6llf",a*a*p,a*a*2);
return 0;
}
```
by ping_fan @ 2018-07-08 23:05:29
谢谢，过了
```cpp
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<sstream>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
#include<iomanip>
#include<time.h>
using namespace std;
int main()
{
double a,p=3.141592653589783238462643383279;
cin>>a;
printf("%.6lf\n%.6lf",a*a*p,a*a*2);
return 0;
}
```
by ping_fan @ 2018-07-08 23:07:32
# 希望更丰富的展现？使用 [Markdown](Markdown)
by 大犇≠大奔 @ 2019-10-14 23:32:21