/in/foo.cc: In function 'int main()':
/in/foo.cc:43:4: error: reference to 'hash' is ambiguous
    hash[i]=dis[i]=0;
    ^~~~
/in/foo.cc:12:5: note: candidates are: int hash [1110]
 int hash[maxn];
     ^~~~
In file included from /usr/include/c++/6/bits/stl_bvector.h:1262:0,
                 from /usr/include/c++/6/vector:65,
                 from /in/foo.cc:2:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:54:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j=0;j<v[q[l]].size();j++)
                 ~^~~~~~~~~~~~~~~
/in/foo.cc:55:10: error: reference to 'hash' is ambiguous
     if (!hash[v[q[l]][j]]){
          ^~~~
/in/foo.cc:12:5: note: candidates are: int hash [1110]
 int hash[maxn];
     ^~~~
In file included from /usr/include/c++/6/bits/stl_bvector.h:1262:0,
                 from /usr/include/c++/6/vector:65,
                 from /in/foo.cc:2:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:59:6: error: reference to 'hash' is ambiguous
      hash[v[q[l]][j]]=1;
      ^~~~
/in/foo.cc:12:5: note: candidates are: int hash [1110]
 int hash[maxn];
     ^~~~
In file included from /usr/include/c++/6/bits/stl_bvector.h:1262:0,
                 from /usr/include/c++/6/vector:65,
                 from /in/foo.cc:2:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~