剑指offer——面试题17：合并两个排序的链表

ListNode* Merge(ListNode* pHead1, ListNode* pHead2){    if(pHead1 == NULL)        return pHead2;    else if(pHead2 == NULL)        return pHead1;    ListNode* pMergedHead = NULL;    if(pHead1->m_nValue < pHead2->m_nValue)    {        pMergedHead = pHead1;        pMergedHead->m_pNext = Merge(pHead1->m_pNext, pHead2);    }    else    {        pMergedHead = pHead2;        pMergedHead->m_pNext = Merge(pHead1, pHead2->m_pNext);    }    return pMergedHead;}