Compilare: user.cpp: In function ‘void make_graph(int)’: user.cpp:24:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); ++i) { ^ user.cpp:33:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < v.size(); ++j) { ^ user.cpp: In function ‘bool verif(int, int)’: user.cpp:45:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); ++i){ ^