0.code

/*
// 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) {
        if(head==null){
            return null;
        }
        Map<Node,Node> map = new HashMap<>();
        Node cur = head;
        while(cur!=null){
            Node temp = new Node(cur.val);
            map.put(cur,temp);
            cur = cur.next;
        }
        Node cur1 = head;
        while(cur1!=null){
            map.get(cur1).next = map.get(cur1.next);
            map.get(cur1).random = map.get(cur1.random);
            cur1 = cur1.next;
        }
        return map.get(head);
    }
}