/in/foo.cc: In function 'bool spfa(int)':
/in/foo.cc:22:2: error: reference to 'hash' is ambiguous
  hash[1]++;
  ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:34:6: error: reference to 'hash' is ambiguous
      hash[i]++;
      ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:35:11: error: reference to 'hash' is ambiguous
      if ((hash[i] > 1 && dist[i] < 0) || hash[i] > n-1) {
           ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:35:42: error: reference to 'hash' is ambiguous
      if ((hash[i] > 1 && dist[i] < 0) || hash[i] > n-1) {
                                          ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:48:6: error: reference to 'hash' is ambiguous
      hash[i]++;
      ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:49:11: error: reference to 'hash' is ambiguous
      if ((hash[i] > 1 && dist[i] < 0) || hash[i] > n-1)
           ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:49:42: error: reference to 'hash' is ambiguous
      if ((hash[i] > 1 && dist[i] < 0) || hash[i] > n-1)
                                          ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:67:10: error: reference to 'hash' is ambiguous
   memset(hash, 0, sizeof(hash));
          ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:67:26: error: reference to 'hash' is ambiguous
   memset(hash, 0, sizeof(hash));
                          ^~~~
/in/foo.cc:14:5: note: candidates are: int hash [1001]
 int hash[INF], dist[INF], p[INF][INF], path[INF][INF], worm[INF][INF], t;
     ^~~~
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/stdexcept:39,
                 from /usr/include/c++/6/array:39,
                 from /usr/include/c++/6/tuple:39,
                 from /usr/include/c++/6/bits/stl_map.h:63,
                 from /usr/include/c++/6/map:61,
                 from /in/foo.cc:5:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc: In function 'bool spfa(int)':
/in/foo.cc:56:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^