Compilare: user.c: In function ‘main’: user.c:4:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("obj.in","r",stdin),freopen("obj.out","w",stdout),scanf("%d",&j); ^ user.c:4:40: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("obj.in","r",stdin),freopen("obj.out","w",stdout),scanf("%d",&j); ^ user.c:4:68: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("obj.in","r",stdin),freopen("obj.out","w",stdout),scanf("%d",&j); ^ user.c:6:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^