Language: C++


#include <iostream>
#include <vector>
#include <queue>
using namespace std;

int main(){
  int n;
  vector<int> mat[100];
  cin >> n;
  for(int i=0;i<n;i++){
    int u,k;
    cin >> u >> k;
    for(int j=0;j<k;j++){
      int v;
      cin >> v;
      mat[i].push_back(v);
    }
  }

  int d[100];
  for(int i=0;i<n;i++) d[i]=(-1);

  queue<int> nb;
  nb.push(0);
  d[0]=0;

  while(!nb.empty()){
    for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      if(d[*it]==-1){
        d[*it]=d[nb.front()]+1;
        nb.push(*it);
      }
    }
    nb.pop();
  }

  for(int i=1;i<=n;i++)
    cout << i << ' ' << d[i-1] << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:29:60: error: no match for 'operator!=' (operand types are 'std::vector<int>::iterator' and '<unresolved overloaded function type>')
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                          ~~^~~~~~~~~~~~~~~~~~~~~
      |                                                          |                   |
      |                                                          |                   <unresolved overloaded function type>
      |                                                          std::vector<int>::iterator
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:2:
/usr/include/c++/14/bits/postypes.h:197:5: note: candidate: 'template<class _StateT> bool std::operator!=(const fpos<_StateT>&, const fpos<_StateT>&)'
  197 |     operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:197:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::fpos<_StateT>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
In file included from /usr/include/c++/14/string:43,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/bits/allocator.h:243:5: note: candidate: 'template<class _T1, class _T2> bool std::operator!=(const allocator<_CharT>&, const allocator<_T2>&)'
  243 |     operator!=(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:243:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::allocator<_CharT>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
In file included from /usr/include/c++/14/string:48:
/usr/include/c++/14/bits/stl_iterator.h:455:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  455 |     operator!=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:455:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::reverse_iterator<_Iterator>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  500 |     operator!=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::reverse_iterator<_Iterator>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1686 |     operator!=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::move_iterator<_IteratorL>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1753 |     operator!=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::move_iterator<_IteratorL>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1052:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator!=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1052 |     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1052:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::pair<_T1, _T2>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:651:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  651 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:651:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/string_view:658:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  658 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:658:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/string_view:666:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  666 |     operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:666:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::vector<int>::const_iterator (std::vector<int>::*)() const noexcept'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
a.cc:29:78: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::vector<int>::iterator (std::vector<int>::*)() noexcept'
a.cc:29:78: note:   couldn't deduce template parameter '_CharT'
/usr/include/c++/14/bits/basic_string.h:3833:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3833 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3833:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   'std::vector<int>::iterator' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/bits/basic_string.h:3847:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3847 |     operator!=(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3847:5: note:   template argument deduction/substitution failed:
a.cc:29:78: note:   mismatched types 'const _CharT*' and '__gnu_cxx::__normal_iterator<int*, std::vector<int> >'
   29 |     for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end;it++){
      |                                                                              ^~~
/usr/include/c++/14/bits/basic_string.h:3860:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3860 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~