/in/foo.cc: In function 'void add(int, int, int)':
/in/foo.cc:25:23: error: reference to 'next' is ambiguous
  to[cnt]=b,val[cnt]=c,next[cnt]=head[a],head[a]=cnt;
                       ^~~~
/in/foo.cc:12:14: note: candidates are: int next [200010]
 int to[maxm],next[maxm],val[maxm],head[maxn],dis[maxn],vis[maxn],d[maxn],q[maxn<<1],f[51][maxn];
              ^~~~
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/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:3:
/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 work()':
/in/foo.cc:45:27: error: reference to 'next' is ambiguous
   for(i=head[u]; i!=-1; i=next[i])  if(dis[to[i]]>dis[u]+val[i]) dis[to[i]]=dis[u]+val[i],pq.push(mp(-dis[to[i]],to[i]));
                           ^~~~
/in/foo.cc:12:14: note: candidates are: int next [200010]
 int to[maxm],next[maxm],val[maxm],head[maxn],dis[maxn],vis[maxn],d[maxn],q[maxn<<1],f[51][maxn];
              ^~~~
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/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:3:
/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:56:49: error: reference to 'next' is ambiguous
  for(i=1; i<=n; i++)    for(j=head[i]; j!=-1; j=next[j])  if(dis[i]+val[j]==dis[to[j]])   d[to[j]]++;
                                                 ^~~~
/in/foo.cc:12:14: note: candidates are: int next [200010]
 int to[maxm],next[maxm],val[maxm],head[maxn],dis[maxn],vis[maxn],d[maxn],q[maxn<<1],f[51][maxn];
              ^~~~
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/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:3:
/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:61:27: error: reference to 'next' is ambiguous
   for(i=head[u]; i!=-1; i=next[i])  if(dis[u]+val[i]==dis[to[i]])
                           ^~~~
/in/foo.cc:12:14: note: candidates are: int next [200010]
 int to[maxm],next[maxm],val[maxm],head[maxn],dis[maxn],vis[maxn],d[maxn],q[maxn<<1],f[51][maxn];
              ^~~~
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/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:3:
/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:76:57: error: reference to 'next' is ambiguous
   for(i=1; i<=tot; i++)  for(u=q[i],j=head[u]; j!=-1; j=next[j])   if(dis[u]+val[j]==dis[to[j]])
                                                         ^~~~
/in/foo.cc:12:14: note: candidates are: int next [200010]
 int to[maxm],next[maxm],val[maxm],head[maxn],dis[maxn],vis[maxn],d[maxn],q[maxn<<1],f[51][maxn];
              ^~~~
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/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:3:
/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:80:50: error: reference to 'next' is ambiguous
   for(i=1; i<=n; i++)    for(j=head[i]; j!=-1; j=next[j])  if(dis[i]+val[j]!=dis[to[j]]&&k+dis[i]+val[j]-dis[to[j]]<=K)
                                                  ^~~~
/in/foo.cc:12:14: note: candidates are: int next [200010]
 int to[maxm],next[maxm],val[maxm],head[maxn],dis[maxn],vis[maxn],d[maxn],q[maxn<<1],f[51][maxn];
              ^~~~
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/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:3:
/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
     ^~~~