Compilare: user.cpp: In function ‘void Read()’: user.cpp:12:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘void DFS(int)’: user.cpp:25:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[node].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(Sol.size()!=N-1) ^ user.cpp:46:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<Sol.size();i++) ^