Compilare: user.cpp: In function ‘void read()’: user.cpp:26:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < ini_list[i].size(); j++){ ^ user.cpp:28:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < ini_list[ini_list[i][j].first].size(); k++) ^ user.cpp: In function ‘void add_false_vertex()’: user.cpp:37:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (list[i].size() != in_gr[i]) ^ user.cpp:38:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (list[i].size() > in_gr[i]) list[0].push_back(i), in_gr[i]++; ^ user.cpp:37:6: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (list[i].size() != in_gr[i]) ^