/in/foo.cc: In function 'int main()':
/in/foo.cc:45:12: error: reference to 'hash' is ambiguous
   now=top; hash(now);
            ^~~~
/in/foo.cc:10:6: note: candidates are: void hash(ull)
 void hash(ull now)
      ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:46:58: error: reference to 'hash' is ambiguous
   for(i=r+1;i<=n;i++) now=now*pc-fa[i-r][j]*ppc+fa[i][j],hash(now);
                                                          ^~~~
/in/foo.cc:10:6: note: candidates are: void hash(ull)
 void hash(ull now)
      ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~