Language: C++

#include<bits/stdc++.h>
using namespace std;
#define rep(i,j,n) for(int i=(int)(j);i<(int)(n);i++)
#define REP(i,j,n) for(int i=(int)(j);i<=(int)(n);i++)
#define MOD 1000000007
#define int long long
#define ALL(a) (a).begin(),(a).end()
#define vi vector<int>
#define vii vector<vi>
#define pii pair<int,int>
#define priq priority_queue<int>
#define disup(A,key) distance(A.begin(),upper_bound(ALL(A),(int)(key)))
#define dislow(A,key) distance(A.begin(),lower_bound(ALL(A),(int)(key)))
#define tii tuple<int,int,int>
#define Priq priority_queue<int,vi,greater<int>>
#define pb push_back
#define mp make_pair
signed main(){
  int N,M; cin>>N>>M;
  vi A(N);
  rep(i,0,M){
    int X,Y; cin>>X>>Y;
    A[X-1].pb(Y-1);
  }
  vector<set<int>> F(N,-1);
  int S,T: cin>>S>>T:
  T--;
  S--;
  F[S].insert(0);
  queue<pii> Q;
  Q.push(mp(S,0));
  int count=0;
  Q.push(mp(-1,-1)));
  int ans=-1;
  while(Q.size()>1){
    int X=Q.front().first,Y=Q.front().second;
    if(X==T&&Y==0){
      ans=count;
      break;
    }
    if(X==-1)
      count++;
    else{
      Q.pop();
      rep(i,0,A[X].size()){
        if(!F[A[X][i]].count((Y+1)%3)){
          Q.push(mp(F[A[X][i]],(Y+1)%3));
          F[A[X][i]].insert((Y+1)%3);
        }
      }
    }
  }
  cout<<ans<<endl;
  }


Compiler output:
a.cc: In function 'int main()':
a.cc:16:12: error: request for member 'push_back' in 'A.std::vector<long long int>::operator[](((std::vector<long long int>::size_type)(X - 1)))', which is of non-class type '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'}
   16 | #define pb push_back
      |            ^~~~~~~~~
a.cc:23:12: note: in expansion of macro 'pb'
   23 |     A[X-1].pb(Y-1);
      |            ^~
a.cc:25:26: error: no matching function for call to 'std::vector<std::set<long long int> >::vector(long long int&, int)'
   25 |   vector<set<int>> F(N,-1);
      |                          ^
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_vector.h:707:9: note: candidate: 'template<class _InputIterator, class> std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with <template-parameter-2-2> = _InputIterator; _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >]'
  707 |         vector(_InputIterator __first, _InputIterator __last,
      |         ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:707:9: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   deduced conflicting types for parameter '_InputIterator' ('long long int' and 'int')
   25 |   vector<set<int>> F(N,-1);
      |                          ^
/usr/include/c++/14/bits/stl_vector.h:678:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::initializer_list<_Tp>, const allocator_type&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; allocator_type = std::allocator<std::set<long long int> >]'
  678 |       vector(initializer_list<value_type> __l,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:678:43: note:   no known conversion for argument 1 from 'long long int' to 'std::initializer_list<std::set<long long int> >'
  678 |       vector(initializer_list<value_type> __l,
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:659:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, std::__type_identity_t<_Alloc>&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; std::__type_identity_t<_Alloc> = std::allocator<std::set<long long int> >]'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:659:23: note:   no known conversion for argument 1 from 'long long int' to 'std::vector<std::set<long long int> >&&'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |              ~~~~~~~~~^~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::false_type) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; allocator_type = std::allocator<std::set<long long int> >; std::false_type = std::false_type]'
  640 |       vector(vector&& __rv, const allocator_type& __m, false_type)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:635:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::true_type) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; allocator_type = std::allocator<std::set<long long int> >; std::true_type = std::true_type]'
  635 |       vector(vector&& __rv, const allocator_type& __m, true_type) noexcept
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:635:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:624:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&, std::__type_identity_t<_Alloc>&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; std::__type_identity_t<_Alloc> = std::allocator<std::set<long long int> >]'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:624:28: note:   no known conversion for argument 1 from 'long long int' to 'const std::vector<std::set<long long int> >&'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |              ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >]'
  620 |       vector(vector&&) noexcept = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:601:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >]'
  601 |       vector(const vector& __x)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:601:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:569:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const value_type&, const allocator_type&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; size_type = long unsigned int; value_type = std::set<long long int>; allocator_type = std::allocator<std::set<long long int> >]'
  569 |       vector(size_type __n, const value_type& __value,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:569:47: note:   no known conversion for argument 2 from 'int' to 'const std::vector<std::set<long long int> >::value_type&' {aka 'const std::set<long long int>&'}
  569 |       vector(size_type __n, const value_type& __value,
      |                             ~~~~~~~~~~~~~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const allocator_type&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; size_type = long unsigned int; allocator_type = std::allocator<std::set<long long int> >]'
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:51: note:   no known conversion for argument 2 from 'int' to 'const std::vector<std::set<long long int> >::allocator_type&' {aka 'const std::allocator<std::set<long long int> >&'}
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |                             ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const allocator_type&) [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >; allocator_type = std::allocator<std::set<long long int> >]'
  542 |       vector(const allocator_type& __a) _GLIBCXX_NOEXCEPT
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:531:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector() [with _Tp = std::set<long long int>; _Alloc = std::allocator<std::set<long long int> >]'
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:531:7: note:   candidate expects 0 arguments, 2 provided
a.cc:26:10: error: found ':' in nested-name-specifier, expected '::'
   26 |   int S,T: cin>>S>>T:
      |          ^
      |          ::
a.cc:26:9: error: 'T' has not been declared
   26 |   int S,T: cin>>S>>T:
      |         ^
a.cc:26:15: error: qualified-id in declaration before '>>' token
   26 |   int S,T: cin>>S>>T:
      |               ^~
a.cc:33:20: error: expected ';' before ')' token
   33 |   Q.push(mp(-1,-1)));
      |                    ^
      |                    ;
a.cc:37:11: error: 'T' was not declared in this scope
   37 |     if(X==T&&Y==0){
      |           ^
a.cc:45:20: error: request for member 'size' in 'A.std::vector<long long int>::operator[](((std::vector<long long int>::size_type)X))', which is of non-class type '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'}
   45 |       rep(i,0,A[X].size()){
      |                    ^~~~
a.cc:3:47: note: in definition of macro 'rep'
    3 | #define rep(i,j,n) for(int i=(int)(j);i<(int)(n);i++)
      |                                               ^
a.cc:46:19: error: invalid types '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type {aka long long int}[long long int]' for array subscript
   46 |         if(!F[A[X][i]].count((Y+1)%3)){
      |                   ^
a.cc:47:27: error: invalid types '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type {aka long long int}[long long int]' for array subscript
   47 |           Q.push(mp(F[A[X][i]],(Y+1)%3));
      |                           ^
a.cc:48:17: error: invalid types '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type {aka long long int}[long long int]' for array subscript
   48 |           F[A[X][i]].insert((Y+1)%3);
      |                 ^