DSA · Theory

Symmetric Binary Tree

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Symmetric Binary Tree

Symmetric Binary Tree sits in a file explorer. Rohit’s job is folder on disk. Write that first.

Keep Symmetric Binary Tree small. Rohit should finish folder on disk in a few lines, not a 40-line dump.

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

Use Symmetric Binary Tree when folder on disk must stay clear. If a simpler DSA step works, use that instead.

Symmetric Binary Tree miss — unbalanced BST becoming a list. Fix it before you talk about advanced DSA.

Place Symmetric Binary Tree next to nearby DSA work — left < root < right is the link.

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

Exam tip

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

Example

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

def inorder(n):
    if not n:
        return []
    return inorder(n.left) + [n.val] + inorder(n.right)

root = Node(2, Node(1), Node(3))
print(inorder(root))

Symmetric Binary Tree — inorder walks left → node → right (sorted order for a BST).

Short notes

DefSymmetric Binary Tree — Rohit uses it for folder on disk in a file explorer.
RuleSymmetric Binary Tree → left < root < right.
RememberSymmetric Binary Tree + time vs memory (a file explorer).
UseSymmetric Binary Tree in a file explorer (folder on disk).
TrapSymmetric Binary Tree — unbalanced BST becoming a list.
ExSymmetric Binary Tree → folder on disk.

class Node: def __init__(self, val, left=None, right=None): self.val, self.left, self.right = val, left, right def inorder(n): if not n: return [] return inorder(n.left) + [n.val] + inorder(n.right) root = Node(2, Node(1), Node(3)) print(inorder(root))

Symmetric Binary Tree

Example

Short notes

Questions

Symmetric Binary Tree

Example

Short notes

Questions