运行 ID: 39389

Main.cc:2:7: error: expected nested-name-specifier before ‘namnespace’
 using namnespace std;
       ^~~~~~~~~~
Main.cc: In function ‘int main()’:
Main.cc:5:2: error: ‘cin’ was not declared in this scope
  cin>>n;
  ^~~
Main.cc:5:2: note: suggested alternative:
In file included from Main.cc:1:0:
/usr/include/c++/7/iostream:60:18: note:   ‘std::cin’
   extern istream cin;  /// Linked to standard input
                  ^~~
Main.cc:7:3: error: ‘cout’ was not declared in this scope
   cout<<"positive";
   ^~~~
Main.cc:7:3: note: suggested alternative:
In file included from Main.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output
                  ^~~~
Main.cc:10:4: error: ‘cout’ was not declared in this scope
    cout<<"zero";
    ^~~~
Main.cc:10:4: note: suggested alternative:
In file included from Main.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output
                  ^~~~
Main.cc:12:4: error: ‘cout’ was not declared in this scope
    cout<<"negative";
    ^~~~
Main.cc:12:4: note: suggested alternative:
In file included from Main.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output
                  ^~~~