Compilare: user.cpp: In function ‘int main()’: user.cpp:42:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[x.second].size(); i++) ^ user.cpp:61:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[x.second].size(); i++) ^ user.cpp:80:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[x.second].size(); i++) ^ user.cpp:111:19: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] y = prea[y]; ^