Compilare: user.cpp: In member function ‘bool& UMap::operator[](int)’: user.cpp:94:27: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null] res[buff].nxt = NULL; ^ user.cpp:108:27: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null] res[buff].nxt = NULL; ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:15:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^