/in/foo.cc:2:7: error: expected nested-name-specifier before 'name'
 using name space std;
       ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:8:1: error: 'cin' was not declared in this scope
 cin>>n;
 ^~~
/in/foo.cc:8:1: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
/in/foo.cc:23:21: error: 't' was not declared in this scope
 for(int i=0;i<n-1;i+t)
                     ^