Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ user.cpp: In function ‘void solve(int)’: user.cpp:42:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:72:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[a].push_back(b); ^