DSA · Theory

Palindromic Tree

Theory

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If you can teach Palindromic Tree using folder on disk, you know it. If you only know the heading, you don’t.

For Palindromic Tree, Big-O is in play. Don’t blame it until you have traced folder on disk.

Palindromic Tree exists so Meera can keep folder on disk correct in a file explorer.

Meera ships Palindromic Tree in a file explorer. That is the use case worth saying.

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

Palindromic Tree is not a lonely heading. Meera ties it to folder on disk.

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

Exam tip

Say Palindromic Tree in one breath, then left < root < right, then unbalanced BST becoming a list.

# Palindromic Tree
data = [4, 1, 3]
print("start", data)
if data[0] > data[1]:
    data[0], data[1] = data[1], data[0]
print("after one step", data)

Palindromic Tree: dry-run [4, 1, 3]. Say the list after one step.