Eroare de compilare: user.c: In function ‘main’: user.c:17:24: error: ‘i’ undeclared (first use in this function) N_2_i_2 = ((N/2) - i)/2; ^ user.c:17:24: note: each undeclared identifier is reported only once for each function it appears in user.c:19:37: error: called object ‘N_6’ is not a function or function pointer fprintf(file2, "%lld\n", N_6(N_2_i_2+1)-(N_6*N_6+1)/2); ^ user.c:7:11: note: declared here long long N_6, N_2_i_2; ^ user.c:12:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &T); ^ user.c:15:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &N); ^