DSA · Theory

Largest BST in Binary Tree

← All stacks

Theory

286/810

Largest BST in Binary Tree

Don’t start Largest BST in Binary Tree with jargon. Start with folder on disk. That is the whole point.

For Largest BST in Binary Tree, a dry-run table is in play. Don’t blame it until you have traced folder on disk.

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

Largest BST in Binary Tree shows up in a file explorer. Name folder on disk, not “a real-world scenario”.

If folder on disk breaks under Largest BST in Binary Tree, check unbalanced BST becoming a list first.

After Largest BST in Binary Tree, Farhan should still remember unbalanced BST becoming a list.

Close Largest BST in Binary Tree with: “If I skip it, folder on disk goes wrong like this: unbalanced BST becoming a list.”

Diagram

Exam tip

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

Example

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

def insert(root, val):
    if root is None:
        return Node(val)
    if val < root.val:
        root.left = insert(root.left, val)
    elif val > root.val:
        root.right = insert(root.right, val)
    return root

root = None
for v in [5, 2, 7, 1]:
    root = insert(root, v)
print(root.val, root.left.val, root.right.val)

Largest BST in Binary Tree — bST invariant: left < node < right — enables log-time search when balanced.

Short notes

DefLargest BST in Binary Tree — Farhan uses it for folder on disk in a file explorer.
RuleLargest BST in Binary Tree → left < root < right.
RememberLargest BST in Binary Tree + a dry-run table (a file explorer).
UseLargest BST in Binary Tree in a file explorer (folder on disk).
TrapLargest BST in Binary Tree — unbalanced BST becoming a list.
ExLargest BST in Binary Tree → folder on disk.

class Node: def __init__(self, val): self.val = val self.left = None self.right = None def insert(root, val): if root is None: return Node(val) if val < root.val: root.left = insert(root.left, val) elif val > root.val: root.right = insert(root.right, val) return root root = None for v in [5, 2, 7, 1]: root = insert(root, v) print(root.val, root.left.val, root.right.val)

Largest BST in Binary Tree

Example

Short notes

Questions

Largest BST in Binary Tree

Example

Short notes

Questions