Compilare: user.c: In function ‘main’: user.c:7:11: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("difprim.in","r",stdin); ^ user.c:8:11: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("difprim.out","w",stdout); ^ user.c:9:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a); ^ user.c:10:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&b); ^ user.c:29:11: warning: ‘d’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(d>dmax) ^ user.c:22:15: warning: ‘n1’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(j = n1+1; j<= b; j++) ^