/in/foo.cc:24:2: error: stray '#' in program
 }#include <iostream>//头文件 
  ^
/in/foo.cc:24:3: error: 'include' does not name a type
 }#include <iostream>//头文件 
   ^~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:30:5: error: redefinition of 'int main()'
 int main()//main函数 
     ^~~~
/in/foo.cc:7:5: note: 'int main()' previously defined here
 int main()//main函数 
     ^~~~