Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:13:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < v[x].size(); k++) ^ user.cpp: In function ‘int main()’: user.cpp:30:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++){ ^