Compilare: user.cpp: In function ‘void Solve()’: user.cpp:62:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int l = 0; l < V[j].size(); l++) ^ user.cpp:58:22: warning: unused variable ‘first’ [-Wunused-variable] bool first = 0; ^ user.cpp:91:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < V[j].size(); k++) ^