Compilare: user.cpp: In function ‘long long int read_nr()’: user.cpp:20:30: warning: NULL used in arithmetic [-Wpointer-arith] for( j=0 , nr=0; sir[j]!=NULL ; j++){ ^ user.cpp: In function ‘int main()’: user.cpp:37:36: warning: NULL used in arithmetic [-Wpointer-arith] for( j=0 , nr=0; sir[j] != NULL ; j++){ ^ user.cpp: In function ‘long long int read_nr()’: user.cpp:18:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",sir); ^ user.cpp: In function ‘int main()’: user.cpp:30:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dtcsu.in","r",stdin); ^ user.cpp:31:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dtcsu.out","w",stdout); ^ user.cpp:35:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",sir); ^