Compilare: user.cpp: In function ‘void graf()’: user.cpp:110:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[i].size(); ++j) ^ user.cpp: In function ‘int main()’: user.cpp:153:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[i].size(); ++j) ^ user.cpp:166:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[i].size(); ++j) ^