Compilare: user.cpp: In function ‘void Solve(int)’: user.cpp:16:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < arb[nod].size(); ++i) Solve(arb[nod][i]); ^ user.cpp:21:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < arb[nod].size(); ++j) ^