mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-18 09:31:58 +00:00
13 lines
201 B
C++
13 lines
201 B
C++
|
#include <bits/stdc++.h>
|
||
|
|
||
|
using namespace std;
|
||
|
|
||
|
const double pi = 3.14159;
|
||
|
|
||
|
int main() {
|
||
|
double r;
|
||
|
cin >> r;
|
||
|
cout << "A=" << fixed << setprecision(4) << pi * r * r << endl;
|
||
|
return 0;
|
||
|
}
|