[LeetCode]复制带随机指针的链表

题目#

 

代码#

/*
// Definition for a Node.
class Node {
public:
    int val;
    Node* next;
    Node* random;

    Node() {}

    Node(int _val, Node* _next, Node* _random) {
        val = _val;
        next = _next;
        random = _random;
    }
};
*/
class Solution {
public:
    Node* copyRandomList(Node* head) {
        if(head==nullptr)
            return nullptr;
        auto originPtr=head;
        Node* newHead=new Node(head->val,nullptr,nullptr);
        auto ptr=newHead;
        //先深拷贝结点
        while(originPtr->next!=nullptr)
        {
            auto node=new Node(originPtr->next->val,nullptr,nullptr);
            ptr->next=node;
            ptr=ptr->next;
            originPtr=originPtr->next;
        }
        originPtr=head;
        ptr=newHead;
        //复制随机指针
        while(originPtr!=nullptr)
        {
            //当前结点有随机指针
            if(originPtr->random!=nullptr)
            {
                auto tempOld=head;
                auto tempNew=newHead;
                while(tempOld!=nullptr)
                {
                    if(tempOld==originPtr->random)
                    {
                        ptr->random=tempNew;
                        break;
                    }else
                    {
                        tempOld=tempOld->next;
                        tempNew=tempNew->next;
                    }
                }
            }
            originPtr=originPtr->next;
            ptr=ptr->next;
        }
        return newHead;
    }
};