[剑指Offer] 25.复杂链表的复制

/*
struct RandomListNode {
    int label;
    struct RandomListNode *next, *random;
    RandomListNode(int x) :
            label(x), next(NULL), random(NULL) {
    }
};
*/
class Solution
{
public:
    //在旧链表中创建新链表，此时不处理新链表的兄弟结点
    void CloneNode(RandomListNode* pHead)
    {
        RandomListNode* pNode = pHead;
        while(pNode != NULL)
        {
            RandomListNode* newNode = new RandomListNode(pNode->label);
            newNode->next = pNode->next;

            pNode->next = newNode;
            pNode = newNode->next;
        }
    }
    //根据旧链表的random结点，初始化新链表的random结点
    void CloneRandomNode(RandomListNode* pHead)
    {
        RandomListNode* pNode = pHead;
        while(pNode != NULL)
        {
            RandomListNode* pNewNode = pNode->next;
            if(pNode->random != NULL)
                pNewNode->random = pNode->random->next;
            pNode = pNewNode->next;
        }
    }
    //从旧链表中拆分得到新链表
    RandomListNode* getNewList(RandomListNode* pHead)
    {
        RandomListNode* pNode = pHead;
        RandomListNode* pClonedHead = pHead->next;
        RandomListNode* pClonedNode = pHead->next;
        
        pNode->next = pClonedNode->next;
        pNode = pNode->next;

        //循环
        while(pNode!=NULL)
        {
            pClonedNode->next = pNode->next;
            pClonedNode = pClonedNode->next; 
            pNode->next = pClonedNode->next; 
            pNode = pNode->next;
        }
        return pClonedHead;
    }
    RandomListNode* Clone(RandomListNode* pHead)
    {
        if(pHead==NULL) return NULL;
        CloneNode(pHead);
        CloneRandomNode(pHead);
        return getNewList(pHead);
    }
};