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Insertion in BST

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Insertion in BST

Insertion in BST sits in a file explorer. Arun’s job is folder on disk. Write that first.

Insertion in BST on the board — left < root < right. Then say what folder on disk looks like after.

Without Insertion in BST, a file explorer gets messy and folder on disk is hard to trust.

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

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

Insertion in BST is not a lonely heading. Arun ties it to folder on disk.

One breath for Insertion in BST, then folder on disk, then unbalanced BST becoming a list. Sit down.

Diagram

Exam tip

For Insertion in BST: definition + a file explorer + one failure.

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)

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

Short notes

DefInsertion in BST — Arun uses it for folder on disk in a file explorer.
RuleInsertion in BST → left < root < right.
RememberInsertion in BST + a dry-run table (a file explorer).
UseInsertion in BST in a file explorer (folder on disk).
TrapInsertion in BST — unbalanced BST becoming a list.
ExInsertion 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)

Insertion in BST

Example

Short notes

Questions

Insertion in BST

Example

Short notes

Questions