学步园

链表相邻元素翻转，如a->b->c->d->e->f-g，翻转后变为：b->a->d->c->f->e->g

struct Node
{
      char value;
      Node *next;
};

Node* reverse(Node *head)
{
      if (NULL == head || head->next == NULL)
      {
          return head;
      }

      Node *q = head;
      Node *p = head->next;
      Node *newHead = p;
      q->next = p->next;
      p->next = q;

      Node *prev = q;
      q = prev->next;
      while (q != NULL)
     {
          p = q->next;
          if (p == NULL)
          {
              break;
          }
          q->next = p->next;
          prev->next = p;
          p->next = q;
          prev = q;
          q= prev->next;
      }

      return newHead;
}