Compilare: user.c: In function ‘main’: user.c:5:17: warning: variable ‘r’ set but not used [-Wunused-but-set-variable] long int n,a,b,r,aux; ^ user.c:10:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%ld",&n); ^ user.c:13:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%ld %ld",&a,&b); ^