Compilare: user.c: In function ‘main’: user.c:13:3: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d", &a, &b, &n); ^ user.c:15:5: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%lld", &cer, &A); ^ user.c:27:24: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] sol[i] = 1LL * k * (k - 1) / 2; ^