void reorderList(ListNode *head) {
if (NULL == head || NULL == head->next)
return;
ListNode *pMid = findMidPos(head);
pMid = reverseList(pMid);
head = Merge(head, pMid);
}
ListNode* sortList(ListNode* head) {
if (!head || head->next == NULL)
return head;
ListNode *mid = findMidPos(head);
ListNode *right_head = mid->next;
mid->next = NULL;
// divide
head = sortList(head);
right_head = sortList(right_head);
// merge
head = merge(head, right_head);
return head;
}
void reorderList(ListNode *head)
{
ListNode *pMid = findMidPos(head);
pMid = reverseList(pMid);
head = Merge(head, pMid);
}