Compilare: user.c: In function ‘main’: user.c:24:5: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘int’ [-Wformat=] fprintf(out, "%llu\n", (1 << count_pfacts(b / a))); ^ user.c: In function ‘count_pfacts’: user.c:45:22: warning: unused variable ‘d’ [-Wunused-variable] uint64_t count = 0, d = 2; ^ user.c: In function ‘main’: user.c:16:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%llu%*c", &t); ^ user.c:20:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%llu%*c%llu%*c", &a, &b); ^