2-2.cpp

来自「完全正确的thinking in c++第二章习题答案」· C++ 代码 · 共 11 行

#include<iostream>
//#include<cstdio>
using namespace std;
void main ()
{float s;
 int r;
cout<<"please enter r:";
cin>>r;
s=3.14*r*r;
 cout<<"s="<<s<<endl;
}