Run ID 作者 问题 语言 测评结果 Time Memory 代码长度 提交时间
143520 张晓冉 04圆的面积 C++ Compile Error 0 MS 0 KB 190 2026-01-16 20:49:21

Tests(0/0):

Code:

#include <iomanip> using namespace std; int main() { double r; double pi = 3.1415926; cin >> r; cout << fixed << setprecision(3) << pi*r*r << endl; return 0; }

Run Info:

Main.cc: In function 'int main()':
Main.cc:8:5: error: 'cin' was not declared in this scope
     cin >> r;
     ^
Main.cc:9:5: error: 'cout' was not declared in this scope
     cout << fixed << setprecision(3) << pi*r*r << endl;
     ^
Main.cc:9:51: error: 'endl' was not declared in this scope
     cout << fixed << setprecision(3) << pi*r*r << endl;
                                                   ^