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

    public Node(int val) {
        this.val = val;
        this.next = null;
        this.random = null;
    }
}
*/
class Solution {
   public Node copyRandomList(Node head) {
       HashMap<Node,Node> map = new HashMap<>();
       Node old = head;
       Node New = null;
       while(old!= null){
           New = new Node(old.val);
           map.put(old,New);
           old = old.next;
       }
       old = head;
       while (old!=null){
           New = map.get(old);
           New.next = map.get(old.next);
           New.random = map.get(old.random);
           old = old.next;
       }
       return map.get(head);
    }
}