Compilare: main.c: In function 'read': main.c:32:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &C); ^~~~~~~~~~~~~~~~~~~~ main.c:33:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%s", s); ^~~~~~~~~~~~~~~~~~~ main.c:34:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d %lld", &a, &b, &E); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c: In function 'parse': main.c:39:9: warning: 'sign' may be used uninitialized in this function [-Wmaybe-uninitialized] int sign; ^~~~