Compilare: user.cpp: In function ‘sol dfs(int)’: user.cpp:23:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < N[nod].size (); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:40:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] N[x].push_back (y); ^ user.cpp:41:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] t[y]++; ^