提交时间:2025-10-17 14:36:06
运行 ID: 70082
#include <iostream> #include <iomanip> using namespace std; int main() { const double PI = 3.14159; double r; cin >> r; double diameter = 2 * r; double circumference = 2 * PI * r; double area = PI * r * r; cout << fixed << setprecision(4); cout << diameter << " " << circumference << " " << area << endl; return 0; }