Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:15:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < v[k].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:61:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) ^ user.cpp:66:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < bad.size(); i++) ^