1 package leetcode; 2  3 class RandomListNode { 4     int label; 5     RandomListNode next, random; 6  7     public RandomListNode(int x) { 8         this.label = x; 9     }10 }11 12 public class CopyListRandom {13     public RandomListNode copyRandomList(RandomListNode head) {14         if(head==null)return head;15         RandomListNode po= head.next;16         RandomListNode p=head;17         while(p!=null){18             RandomListNode newnode=new RandomListNode(p.label);19             po=p.next;20             newnode.next=p.next;21             p.next=newnode;22 23             p=po;            24         }25         p=head;26         while(p!=null){27             if(p.random!=null){28             p.next.random=p.random.next;29         }30             p=p.next.next;31         }32         p=head;33         RandomListNode h=head.next;34         RandomListNode q=h;35         while(q!=null){36             p.next=q.next;37             p=q;38             q=q.next;            39         }40         return h;41     }42 }