foo.cc: In function 'int main()':
foo.cc:5:27: error: 'cin' was not declared in this scope
     for(int i=1;i<=10;++i)cin>>a[i];
                           ^~~
foo.cc:5:27: note: suggested alternative:
In file included from foo.cc:2:0:
/usr/include/c++/7/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
foo.cc:6:8: error: 'cin' was not declared in this scope
  int x;cin>>x;
        ^~~
foo.cc:6:8: note: suggested alternative:
In file included from foo.cc:2:0:
/usr/include/c++/7/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
foo.cc:10:2: error: 'cout' was not declared in this scope
  cout<<tot<<endl;
  ^~~~
foo.cc:10:2: note: suggested alternative:
In file included from foo.cc:2:0:
/usr/include/c++/7/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~
foo.cc:10:13: error: 'endl' was not declared in this scope
  cout<<tot<<endl;
             ^~~~
foo.cc:10:13: note: suggested alternative:
In file included from /usr/include/c++/7/iostream:39:0,
                 from foo.cc:2:
/usr/include/c++/7/ostream:590:5: note:   'std::endl'
     endl(basic_ostream<_CharT, _Traits>& __os)
     ^~~~

[Hydro](https://hydro.ac)提供评测服务