Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<A[x].size();j++){ ~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:32:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();i++){ ~^~~~~~~~~ user.cpp:41:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g.size();i++) ~^~~~~~~~~