answer.code:33:12: error: ‘std::set<std::__cxx11::basic_string<char> > dup’ redeclared as different kind of entity
   33 | set<string>dup ;
      |            ^~~
In file included from /usr/include/c++/11/bits/atomic_wait.h:44,
                 from /usr/include/c++/11/bits/atomic_base.h:41,
                 from /usr/include/c++/11/bits/shared_ptr_atomic.h:33,
                 from /usr/include/c++/11/memory:78,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:82,
                 from answer.code:1:
/usr/include/unistd.h:531:12: note: previous declaration ‘int dup(int)’
  531 | extern int dup (int __fd) __THROW __wur;
      |            ^~~
answer.code: In function ‘bool col(long long int, long long int, long long int)’:
answer.code:47:17: error: request for member ‘insert’ in ‘dup’, which is of non-class type ‘int(int) noexcept’
   47 |             dup.insert(r) ;
      |                 ^~~~~~
answer.code: In function ‘bool row(long long int, long long int, long long int)’:
answer.code:65:32: error: request for member ‘count’ in ‘dup’, which is of non-class type ‘int(int) noexcept’
   65 |         if((e.count(rw) or dup.count(rw)) and mode==0)
      |                                ^~~~~
answer.code: In function ‘void build(long long int)’:
answer.code:85:25: error: request for member ‘clear’ in ‘dup’, which is of non-class type ‘int(int) noexcept’
   85 |                     dup.clear() ;
      |                         ^~~~~
answer.code:103:25: error: request for member ‘clear’ in ‘dup’, which is of non-class type ‘int(int) noexcept’
  103 |                     dup.clear() ;
      |                         ^~~~~
answer.code:123:25: error: request for member ‘clear’ in ‘dup’, which is of non-class type ‘int(int) noexcept’
  123 |                     dup.clear() ;
      |                         ^~~~~
answer.code:141:25: error: request for member ‘clear’ in ‘dup’, which is of non-class type ‘int(int) noexcept’
  141 |                     dup.clear() ;
      |                         ^~~~~