void bear_reverse(node * front)
{
node *p, *c, *n;
p = NULL;
c = front;
n = c->next;
while (n != NULL)
{
p = c;
c = n;
n = c->next;
if (p != NULL)
{
p->next = c;
}
}
c->next = p;
front = c;
}