提交时间:2024-11-09 21:17:28

运行 ID: 56202

#include<bits/stdc++.h> using namespace std; int main(){ double a; cin>>a; cout<<fixed<<setprecision(4)<<2*a<<" "; cout<<fixed<<setprecision(4)<<2*a*3.14159<<" "; cout<<fixed<<setprecision(4)<<a*a*3.14159<<" "<<endl; return 0; }