Compilare: user.cpp: In function ‘long long int DFS(int)’: user.cpp:12:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[nod].size();i++) ^ user.cpp: In function ‘char nextch()’: user.cpp:24:31: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,1,MAXBUF,fi); ^