DSA · Theory

Remove extra edge from a BST

← All stacks

Theory

565/810

Remove extra edge from a BST

Sara only reaches for Remove extra edge from a BST when folder on disk has to stay correct in a file explorer.

For Remove extra edge from a BST, Big-O is in play. Don’t blame it until you have traced folder on disk.

Remove extra edge from a BST exists so Sara can keep folder on disk correct in a file explorer.

Sara ships Remove extra edge from a BST in a file explorer. That is the use case worth saying.

If folder on disk breaks under Remove extra edge from a BST, check unbalanced BST becoming a list first.

Place Remove extra edge from a BST next to nearby DSA work — left < root < right is the link.

Close Remove extra edge from a BST 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 Remove extra edge from a BST. 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)

Remove extra edge from a BST — bST invariant: left < node < right — enables log-time search when balanced.

Short notes

DefRemove extra edge from a BST — Sara uses it for folder on disk in a file explorer.
RuleRemove extra edge from a BST → left < root < right.
RememberRemove extra edge from a BST + Big-O (a file explorer).
UseRemove extra edge from a BST in a file explorer (folder on disk).
TrapRemove extra edge from a BST — unbalanced BST becoming a list.
ExRemove extra edge from a BST → 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)

Remove extra edge from a BST

Example

Short notes

Questions

Remove extra edge from a BST

Example

Short notes

Questions