Compilare: user.c: In function ‘main’: user.c:11:19: warning: variable ‘z’ set but not used [-Wunused-but-set-variable] int i,j,n,x,y,z; ^ user.c:13:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker3.in","r",stdin); ^ user.c:14:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker3.out","w",stdout); ^ user.c:15:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.c:16:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.c:21:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^