Compilare: main.c: In function 'main': main.c:40:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &n); ^~~~~~~~~~~~~~~~~~~~ main.c:42:9: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%lu", v + i); ^~~~~~~~~~~~~~~~~~~~~~~~ main.c:43:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &m); ^~~~~~~~~~~~~~~~~~~~ main.c:46:9: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &op, &x); ^~~~~~~~~~~~~~~~~~~~~~~~~~~