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Threaded Binary Tree

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Threaded Binary Tree

Threaded Binary Tree is a DSA idea you prove with folder on disk, not with a slogan.

For Threaded Binary Tree, time vs memory is in play. Don’t blame it until you have traced folder on disk.

Skip Threaded Binary Tree and unbalanced BST becoming a list shows up in a file explorer.

Use Threaded Binary Tree when folder on disk must stay clear. If a simpler DSA step works, use that instead.

Don’t do this with Threaded Binary Tree — unbalanced BST becoming a list. Interviewers spot it in ten seconds.

Place Threaded Binary Tree next to nearby DSA work — left < root < right is the link.

Viva for Threaded Binary Tree — what it is → left < root < right → the mistake (unbalanced BST becoming a list).

Exam tip

Board: folder on disk. Dry-run Threaded Binary Tree. Name the trap: unbalanced BST becoming a list.

Example

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

def inorder(n):
    if not n:
        return []
    return inorder(n.left) + [n.val] + inorder(n.right)

root = Node(2, Node(1), Node(3))
print(inorder(root))

Threaded Binary Tree — inorder walks left → node → right (sorted order for a BST).

Short notes

DefThreaded Binary Tree — Kabir uses it for folder on disk in a file explorer.
RuleThreaded Binary Tree → left < root < right.
RememberThreaded Binary Tree + time vs memory (a file explorer).
UseThreaded Binary Tree in a file explorer (folder on disk).
TrapThreaded Binary Tree — unbalanced BST becoming a list.
ExThreaded Binary Tree → folder on disk.

class Node: def __init__(self, val, left=None, right=None): self.val, self.left, self.right = val, left, right def inorder(n): if not n: return [] return inorder(n.left) + [n.val] + inorder(n.right) root = Node(2, Node(1), Node(3)) print(inorder(root))

Threaded Binary Tree

Example

Short notes

Questions

Threaded Binary Tree

Example

Short notes

Questions