View Compilation Error

0_0_19214432_22202.cpp: In function 'void Tarjan()':
0_0_19214432_22202.cpp:54:12: error: reference to 'hash' is ambiguous
     memset(hash,-1,sizeof(int)*n);
            ^
0_0_19214432_22202.cpp:13:19: note: candidates are: int hash [10001]
 int low[M],idx[M],hash[M];
                   ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/basic_string.h:3068:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/string:52,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/locale_classes.h:40,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/ios_base.h:41,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/ios:42,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/ostream:38,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/iostream:39,
                 from 0_0_19214432_22202.cpp:3:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^