不关注我就要~~~

#include <iostream> using namespace std; double pi=3.14159,r,a,b,c; char d=' '; int main() { cin>>r; a=2 * r; b=2* pi * r; c=pi * r * r; printf("%.4f%.c%.4f%.c%.4f",a,d,b,d,c); return 0; }

#include <bits/stdc++.h> using namespace std; int main() { double r,PI=3.14159; cin>>r; printf("%.4f ",r2); printf("%.4f ",r2PI); printf("%.4f",rr*PI); return 0; }

这题不建议抄题解，不然先去做同提单的前几题吧