Compilare: user.cpp: In function ‘int main()’: user.cpp:33:7: warning: variable ‘a1’ set but not used [-Wunused-but-set-variable] long a1; ^ user.cpp:36:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%ld", &output_dim); ^ user.cpp:41:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%ld", &aux); ^