Compilare: user.cpp: In function ‘void citire()’: user.cpp:15:17: warning: NULL used in arithmetic [-Wpointer-arith] while(a[n]!=NULL) n++; ^ user.cpp:18:17: warning: NULL used in arithmetic [-Wpointer-arith] while(b[m]!=NULL) m++; ^ user.cpp:14:21: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(a,504, in); ^ user.cpp:17:21: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(b,504, in); ^