如何将目录从源树复制到二叉树？

class Node:
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None

def copy_tree(src_root):
    if not src_root:
        return None

    nodes = []
    queue = [src_root]

    while queue:
        node = queue.pop(0)
        nodes.append(node)

        if node.left:
            queue.append(node.left)
        if node.right:
            queue.append(node.right)

    copied_root = Node(nodes[0].val)
    copied_nodes = [copied_root]

    for i in range(1, len(nodes)):
        parent = copied_nodes[i // 2]
        node = Node(nodes[i].val)

        if i % 2 == 0:
            parent.right = node
        else:
            parent.left = node

        copied_nodes.append(node)

    return copied_root