只是测试

YUAN(2).cpp

@@ -0,0 +1,16 @@
+#include<iostream>
+using namespace std;
+
+int main()
+{  
+    const double pi=3.14;
+    double r,c,s;
+    cin>>r;
+    c=2.0*pi*r ;
+    s=pi*r*r;
+    cout<<c<<endl;
+    cout<<s<<endl;
+    
+
+    return 0 ;
+}