Compilare: user.cpp: In function ‘int main()’: user.cpp:32:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ^ user.cpp:45:5: warning: overflow in implicit constant conversion [-Woverflow] sol=100000000007; ^ user.cpp:47:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<a[i].size();j++) ^