Compilare: user.cpp: In function ‘bool insert_lung(int, int, short int)’: user.cpp:45:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<H[r].size();++i) ^ user.cpp:46:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(H[r][i].first==x) ^ user.cpp: In function ‘short int get_lung(int, int)’: user.cpp:62:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<H[r].size();++i) ^ user.cpp:63:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(H[r][i].first==x) ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:34:51: 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 ‘InputReader::InputReader(const char*)’: user.cpp:12:47: 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); ^