#include <iostream>
   #include <fstream>
   #include <string>

   using namespace std;



   int main() {

     cout << "Hello";

   }

当我尝试编译这个程序时，它仍然编译上一个程序:

  #include <iostream>
  #include <fstream>
  #include <string>

  using namespace std;


  int main() {

      int a, b;
      cin >> a >> b;
      cout << a + b << endl;

      return 0;
  }

我在命令提示符下执行gcc code.cpp（文件名）和代码，显示如下:

     c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: 
     C:\Users\User\AppData\Local\Temp\cctefhtT.o:code.cpp:(.text+0x19): undefined reference to 
     `std::cout'
     c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: 
     C:\Users\User\AppData\Local\Temp\cctefhtT.o:code.cpp:(.text+0x1e): undefined reference to 
     `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > 
     (std::basic_ostream<char, std::char_traits<char> >&, char const*)'
      c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: 
      C:\Users\User\AppData\Local\Temp\cctefhtT.o:code.cpp:(.text+0x35): undefined reference to 
      `std::ios_base::Init::~Init()'
      c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: 
      C:\Users\User\AppData\Local\Temp\cctefhtT.o:code.cpp:(.text+0x56): undefined reference to 
      `std::ios_base::Init::Init()'
      collect2.exe: error: ld returned 1 exit status

我的编辑是Sublime的。