Compilare: user.c: In function ‘main’: user.c:20:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("stergeri.in","r",stdin); ^ user.c:21:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("stergeri.out","w",stdout); ^ user.c:22:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&k); ^