A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.
Return a deep copy of the list.
/**
* Definition for singly-linked list with a random pointer.
* struct RandomListNode {
* int label;
* RandomListNode *next, *random;
* RandomListNode(int x) : label(x), next(NULL), random(NULL) {}
* };
*/
class Solution {
public:
RandomListNode *copyRandomList(RandomListNode *head) {
if(head==NULL)
return NULL;
RandomListNode* p=head;
while(p)//复制每个节点
{
RandomListNode* tmp=p->next;
RandomListNode* newNode=new RandomListNode(p->label);
p->next=newNode;
newNode->next=tmp;
p=tmp;
}
p=head;
while(p)//给复制的节点random赋值
{
if(p->random==NULL)
p->next->random=NULL;
else
p->next->random=p->random->next;
p=p->next->next;
}
p=head;
RandomListNode* newHead=p->next;
RandomListNode* p1=newHead;
while(p)
{
p->next=p1->next;
if((p->next)!=NULL)
p1->next=p->next->next;
p=p->next;
p1=p1->next;
}
return newHead;
}
};