Compilare: user.cpp: In function ‘void write()’: user.cpp:43: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void read()’: user.cpp:81: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:86: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:92: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result