Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:111:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<neighbors[nod].size();i++) ^ user.cpp: In function ‘void build_sol(int)’: user.cpp:128:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<neighbors[nod].size();i++) ^ user.cpp: In function ‘void Read(int&)’: user.cpp:93:36: 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,fin); ^ user.cpp:103:36: 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,fin); ^