Compilare: user.c: In function ‘main’: user.c:28:13: warning: unused variable ‘i’ [-Wunused-variable] int n,k,i,x1,x2,x3; ^ user.c:30:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("spion.in","r",stdin); ^ user.c:31:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("spion.out","w",stdout); ^ user.c:33:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&p); ^ user.c:34:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&ch); ^ user.c:36:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&ch); ^