Compilare: user.cpp: In member function ‘void nrx_hash::insert_hash(int)’: user.cpp:61:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < my_hash[position].size(); i ++ ) { ^ user.cpp: In member function ‘void nrx_hash::erase_hash(int)’: user.cpp:74:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < my_hash[position].size(); i ++ ) { ^ user.cpp: In member function ‘int nrx_hash::count_hash(int)’: user.cpp:87:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < my_hash[position].size(); i ++ ) { ^ user.cpp: In function ‘int main()’: user.cpp:112:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "arbore3.out", "w", stdout ); ^ user.cpp: In member function ‘void input_reader::advance()’: user.cpp:19:53: 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 ‘input_reader::input_reader(const char*, const char*)’: user.cpp:26:49: 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 ); ^