foo.cpp: In function 'void findCircle(int, int)':
foo.cpp:24:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < edges[x].size(); i++) {
                       ^
foo.cpp: In function 'void dfs_cir(int, int)':
foo.cpp:42:9: error: reference to 'hash' is ambiguous
     if (hash[x]) return;
         ^
foo.cpp:18:21: note: candidates are: int hash [100005]
 int cir[MAXN], tot, hash[MAXN];
                     ^
In file included from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/basic_string.h:3068:0,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/string:52,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/locale_classes.h:40,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/ios_base.h:41,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ios:42,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/istream:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/sstream:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/complex:45,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ccomplex:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/mingw32/bits/stdc++.h:52,
                 from foo.cpp:1:
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^
foo.cpp:44:5: error: reference to 'hash' is ambiguous
     hash[x] = tot;
     ^
foo.cpp:18:21: note: candidates are: int hash [100005]
 int cir[MAXN], tot, hash[MAXN];
                     ^
In file included from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/basic_string.h:3068:0,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/string:52,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/locale_classes.h:40,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/ios_base.h:41,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ios:42,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/istream:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/sstream:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/complex:45,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ccomplex:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/mingw32/bits/stdc++.h:52,
                 from foo.cpp:1:
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^
foo.cpp:46:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < edges[x].size(); i++) {
                       ^
foo.cpp:54:13: error: reference to 'hash' is ambiguous
         len[hash[x]][hash[e.to]] = len[hash[e.to]][hash[x]] = e.v;
             ^
foo.cpp:18:21: note: candidates are: int hash [100005]
 int cir[MAXN], tot, hash[MAXN];
                     ^
In file included from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/basic_string.h:3068:0,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/string:52,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/locale_classes.h:40,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/ios_base.h:41,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ios:42,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/istream:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/sstream:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/complex:45,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ccomplex:38,
                 from C:/TDM-GCC-