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Module 1: Binary Trees (The Branching Path)

📚 Module 1: Binary Trees

Course ID: DSA-301
Subject: The Branching Path

A Tree is a non-linear data structure where one node points to multiple other nodes. A Binary Tree is a specific type where each node can have at most Two children.

🏗️ Step 1: Anatomy of a Tree

🧩 The Analogy: The Family Tree

  1. Root: The “Great-Grandparent” at the very top. There is only one root.
  2. Parent: A node that points to others.
  3. Child: A node that is pointed to.
  4. Leaf: A node at the very end of a branch with No Children.
  5. Edge: The line (pointer) connecting two nodes.

🏗️ Step 2: Traversal (The “Visit”)

In an array, you just loop from 0 to N. In a tree, how do you visit every node? There are three common ways:

  1. Pre-order: Visit the Root, then Left, then Right. (Good for copying a tree).
  2. In-order: Visit Left, then Root, then Right. (Good for sorted lists).
  3. Post-order: Visit Left, then Right, then Root. (Good for deleting a tree).

🏗️ Step 3: In Code (Python)

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

# Build a small tree
root = Node("Grandparent")
root.left = Node("Parent A")
root.right = Node("Parent B")

🥅 Module 1 Review

  1. Binary: Maximum of 2 children per node.
  2. Root: The single entry point.
  3. Traversal: The specific order in which we visit nodes.

:::tip Slow Learner Note A tree is just a Linked List where each node has two “Next” pointers instead of one! :::