/in/foo.cc: In function 'void add(int, int, int)':
/in/foo.cc:10:5: error: reference to 'next' is ambiguous
next[cnt]=head[x];
^~~~
/in/foo.cc:4:13: note: candidates are: int next [200005]
int head[N],next[N],to[N],w[N],cnt,d[N],flag[N],n,m,maxn,total;
^~~~
In file included from /usr/include/c++/6/bits/stl_algobase.h:66:0,
from /usr/include/c++/6/bits/char_traits.h:39,
from /usr/include/c++/6/ios:40,
from /usr/include/c++/6/istream:38,
from /usr/include/c++/6/sstream:38,
from /usr/include/c++/6/complex:45,
from /usr/include/c++/6/ccomplex:39,
from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_iterator_base_funcs.h:205:5: note: template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
next(_ForwardIterator __x, typename
^~~~
/in/foo.cc: In function 'void spfa()':
/in/foo.cc:29:31: error: reference to 'next' is ambiguous
for(int i=head[k];i;i=next[i])
^~~~
/in/foo.cc:4:13: note: candidates are: int next [200005]
int head[N],next[N],to[N],w[N],cnt,d[N],flag[N],n,m,maxn,total;
^~~~
In file included from /usr/include/c++/6/bits/stl_algobase.h:66:0,
from /usr/include/c++/6/bits/char_traits.h:39,
from /usr/include/c++/6/ios:40,
from /usr/include/c++/6/istream:38,
from /usr/include/c++/6/sstream:38,
from /usr/include/c++/6/complex:45,
from /usr/include/c++/6/ccomplex:39,
from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_iterator_base_funcs.h:205:5: note: template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
next(_ForwardIterator __x, typename
^~~~