dream come true 5!
reverse listrecursion and none-recursion
node?*reverse_list(node?*head)

{
??if(head?==?null?||?head->next?==?null)
??????return?head;
??node?*cur?=?head->next;
??node?*pre?=?head;
??node?*next?=?null;
??while(cur?!=?null)
??
{
?????next?=?cur->next;
?????cur->next?=?pre;
?????pre?=?cur;??
?????cur?=?next;
??}
??head->next?=?null;
??head?=?pre;
??reurn?head;
}
node?*reverse_list(node?*head)

{
??if(head?==?null?||?head->next?==?null)
????return?head;
??node?*cur?=?head->next;
??node?*next?=?null;
??head->next?=?null;
??while(cur?!=?null)
?
{
????next?=?cur->next;
????cur->next?=?head;
????head?=?cur;
????cur?=?next;
?}
??return?head;
??
}