Compilare: user.c: In function ‘main’: user.c:9:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("car.in","r",stdin); ^ user.c:10:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("car.out","w",stdout); ^ user.c:12:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&n,&m); ^ user.c:14:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i%i%i",&x1,&y1,&x2,&y2); ^ user.c:17:28: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] fr(i,0,n)fr(j,0,m)scanf("%i",a[i]+j); ^