Compilare: user.cpp: In function ‘void Solve(int)’: user.cpp:19:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();++i) ^ user.cpp: In function ‘bool cmp(int, int)’: user.cpp:26:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=1;k<a[i].size();k++) ^