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Deletion in BST

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Deletion in BST

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

Keep Deletion in BST small. Neha should finish folder on disk in a few lines, not a 40-line dump.

Skip Deletion in BST and unbalanced BST becoming a list shows up in a file explorer.

Neha ships Deletion in BST in a file explorer. That is the use case worth saying.

Deletion in BST miss — unbalanced BST becoming a list. Fix it before you talk about advanced DSA.

Deletion in BST is not a lonely heading. Neha ties it to folder on disk.

Close Deletion in 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 Deletion in 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)

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

Short notes

DefDeletion in BST — Neha uses it for folder on disk in a file explorer.
RuleDeletion in BST → left < root < right.
RememberDeletion in BST + time vs memory (a file explorer).
UseDeletion in BST in a file explorer (folder on disk).
TrapDeletion in BST — unbalanced BST becoming a list.
ExDeletion in 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)

Deletion in BST

Example

Short notes

Questions

Deletion in BST

Example

Short notes

Questions