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) {}
* };
*/
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 head;
//将oldList的每一个节点之后，插入一个newNode.
RandomListNode *oldListNode = head;
while(oldListNode != NULL)
{
RandomListNode *newListNode = new RandomListNode(oldListNode->label);
newListNode->next = oldListNode->next;
newListNode->random = oldListNode->random;
oldListNode->next = newListNode;
oldListNode = oldListNode->next->next;
}
//update newListNode上的random结点关联的结点
oldListNode = head;
while(oldListNode != NULL)
{
if(oldListNode->random != NULL)
{
oldListNode->next->random = oldListNode->random->next;
}
oldListNode = oldListNode->next->next;
}
//分离oldListNode与newListNode
RandomListNode *newListNode = new RandomListNode(0);
newListNode->next = head;
oldListNode = head;
RandomListNode *resultListNode = newListNode;
while(oldListNode != NULL)
{
newListNode->next = oldListNode->next;
oldListNode->next = newListNode->next->next;
newListNode = newListNode->next;
oldListNode = oldListNode->next;
}
return resultListNode->next;
}
};