复制含有随机指针节点的链表

import java.util.HashMap;

/**
* Created by 糖糖 on 2017/8/7.
*/
public class copyLink {
public static Snode copyLink(Snode head ){
Snode cur = head;
HashMap<Snode,Snode> hashMap = new  HashMap<Snode,Snode>();
while (cur !=null){
hashMap.put(cur,new Snode(cur.data));
cur = cur.next;
}
cur = head;
while (cur != null){
hashMap.get(cur).next = hashMap.get(cur.next);
hashMap.get(cur).rand = hashMap.get(cur.rand);
cur = cur.next;
}
return hashMap.get(head);
}

public  static Snode cpoyLink2(Snode head){
Snode cur = head;
Snode next = null;
//复制链表
while (cur!=null){
next = cur.next;
cur.next = new Snode(cur.data);
cur.next.next = next;
cur = next;
}
//复制rand关系
cur = head;
Snode curcopy = null;
while (cur != null){
next = cur.next.next;
curcopy = cur.next;
curcopy.rand = cur.rand== null?null:cur.rand;
cur = next;
}

//拆分链表
cur = head;
Snode res = head.next;
while (cur != null){
next = cur.next.next;
curcopy = cur.next;
cur.next = next;
curcopy.next = next!=null?next:null;
cur = next;
}
return res;
}

public  static  void  main(String args[]){
Snode s1=new Snode(1);
Snode s2=new Snode(2);
Snode s3=new Snode(3);

s1.next = s2;
s2.next = s3;

s1.rand = s2;
s3.rand = s2;
Snode snode = copyLink(s1);
Snode snode1 = cpoyLink2(s1);
System.out.println(snode.rand.data);
System.out.println(snode1.rand.data);

}
}
class  Snode{
int data;
Snode next;
Snode rand;
public Snode(int data){
this.data=data;
next = null;
rand = null;
}
}