The tree is represented in the same input/output way as normal binary trees where each node is represented as a pair of [val, random_index] where:
val: an integer representing Node.val
random_index: the index of the node (in the input) where the random pointer points to, or null if it does not point to any node.
You will be given the tree in class Node and you should return the cloned tree in class NodeCopy. NodeCopy class is just a clone of Node class with the same attributes and constructors.

Input: root =[[1,null],null,[4,3],[7,0]] Output:[[1,null],null,[4,3],[7,0]] Explanation: The original binary tree is[1,null,4,7]. The random pointer of node one isnull, so it is represented as [1,null]. The random pointer of node 4is node 7, so it is represented as [4,3] where 3is the index of node 7in the array representing the tree. The random pointer of node 7is node 1, so it is represented as [7,0] where 0is the index of node 1in the array representing the tree.
Example 2:
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Input: root =[[1,4],null,[1,0],null,[1,5],[1,5]] Output:[[1,4],null,[1,0],null,[1,5],[1,5]] Explanation: The random pointer of a node can be the node itself.
To clone a binary tree with random pointers, we need to create a copy of each node and ensure that the left, right, and random pointers in the new tree point to the corresponding cloned nodes. We use a hash map to map original nodes to their clones, so we can set the random pointers correctly.