DSA · Theory

Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree

Theory

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Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree

Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree is a DSA topic. In plain words you use it for folder on disk in a file explorer. Don’t start with a slogan — start with that picture.

Smallest example: left < root < right. Type it, run it, and say what you see. If you can do that from memory, you know Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree.

From the example next to this theory: Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree — inorder walks left → node → right (sorted order for a BST).

Trap — unbalanced BST becoming a list. Fix that before you talk about advanced DSA.

Viva: what is Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree? Then show left < root < right. Then name the trap.

Exam tip

What is Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree? Show this: left < root < right. Trap: 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))

Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree — inorder walks left → node → right (sorted order for a BST).

Short notes

DefConstruct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree — folder on disk in a file explorer.
Ruleleft < root < right
Trapunbalanced BST becoming a list
Usea file explorer

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))

Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree

Example

Short notes

Questions

Construct Full Binary Tree using its Preorder Traversal and Preorder Traversal of its Mirror Tree

Example

Short notes

Questions