Eroare de compilare: user.c: In function ‘main’: user.c:13:5: error: ‘k’ undeclared (first use in this function) for(k=1; k<=3; k++){ ^ user.c:13:5: note: each undeclared identifier is reported only once for each function it appears in user.c:14:26: error: ‘i’ undeclared (first use in this function) sigma += (N-2*k)/4 - i + 1; ^ user.c:11:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &N); ^