Compilare: user.cpp: In function ‘int main()’: user.cpp:181:21: warning: unused variable ‘nod’ [-Wunused-variable] int nod = a; ^ user.cpp:188:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G[a].size();i++) ^ user.cpp:195:21: warning: unused variable ‘nod’ [-Wunused-variable] int nod = a; ^ user.cpp: In member function ‘void Reader::advance()’: user.cpp:55:47: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In constructor ‘Reader::Reader(const char*)’: user.cpp:13:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^