Compilare: user.c: In function ‘main’: user.c:33:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%d %d %d", &a, &b, &u); ^ user.c:36:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%d %d", &u1[i], &u2[i]); ^ user.c:39:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%ld", &n); ^ user.c:42:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%d %d %d %d", &x1, &y1, &x2, &y2); ^