Find the kth Largest Element in a Binary Search Tree - Algorithm, Visualization, Examples

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right


def kthLargest(root, k):
    count = 0
    result = None

    def traverse(node):
        nonlocal count, result
        if not node or result is not None:
            return
        traverse(node.right)
        count += 1
        if count == k:
            result = node.val
            return
        traverse(node.left)

    traverse(root)
    return result

# Example usage:
if __name__ == '__main__':
    # Construct a sample BST:
    #         5
    #        / \
    #       3   7
    #      / \   \
    #     2   4   8
    root = TreeNode(5, TreeNode(3, TreeNode(2), TreeNode(4)), TreeNode(7, None, TreeNode(8)))
    k = 2
    print(kthLargest(root, k))