/in/foo.cc: In function 'int hash(int)':
/in/foo.cc:14:7: error: reference to 'map' is ambiguous
 while(map[ret] != -1 && map[ret] != x)
       ^~~
/in/foo.cc:8:5: note: candidates are: int map [6100]
 int map[HASH + 100], f[N * 2 + 100];
     ^~~
In file included from /usr/include/c++/6/map:61:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:81,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/stl_map.h:96:11: note:                 template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map
     class map
           ^~~
/in/foo.cc:14:25: error: reference to 'map' is ambiguous
 while(map[ret] != -1 && map[ret] != x)
                         ^~~
/in/foo.cc:8:5: note: candidates are: int map [6100]
 int map[HASH + 100], f[N * 2 + 100];
     ^~~
In file included from /usr/include/c++/6/map:61:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:81,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/stl_map.h:96:11: note:                 template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map
     class map
           ^~~
/in/foo.cc:16:1: error: reference to 'map' is ambiguous
 map[ret] = x;
 ^~~
/in/foo.cc:8:5: note: candidates are: int map [6100]
 int map[HASH + 100], f[N * 2 + 100];
     ^~~
In file included from /usr/include/c++/6/map:61:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:81,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/stl_map.h:96:11: note:                 template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map
     class map
           ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:32:8: error: reference to 'map' is ambiguous
 memset(map, -1, sizeof(map));
        ^~~
/in/foo.cc:8:5: note: candidates are: int map [6100]
 int map[HASH + 100], f[N * 2 + 100];
     ^~~
In file included from /usr/include/c++/6/map:61:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:81,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/stl_map.h:96:11: note:                 template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map
     class map
           ^~~
/in/foo.cc:32:24: error: reference to 'map' is ambiguous
 memset(map, -1, sizeof(map));
                        ^~~
/in/foo.cc:8:5: note: candidates are: int map [6100]
 int map[HASH + 100], f[N * 2 + 100];
     ^~~
In file included from /usr/include/c++/6/map:61:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:81,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/stl_map.h:96:11: note:                 template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map
     class map
           ^~~
/in/foo.cc:41:5: error: reference to 'hash' is ambiguous
 a = hash(a - 1);
     ^~~~
/in/foo.cc:10:5: note: candidates are: int hash(int)
 int hash(int x)
     ^~~~
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:42:5: error: reference to 'hash' is ambiguous
 b = hash(b);
     ^~~~
/in/foo.cc:10:5: note: candidates are: int hash(int)
 int hash(int x)
     ^~~~
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;
            ^~~~