Function count_nodes

data_structures/binary_tree/distribute_coins.py:82–90

>>> count_nodes(None) 0

(node: TreeNode | None)

    # Validation
    def count_nodes(node: TreeNode | None) -> int:
        """
        >>> count_nodes(None)
        0
        """
        if node is None:
            return 0

        return count_nodes(node.left) + count_nodes(node.right) + 1

    def count_coins(node: TreeNode | None) -> int:
        """