Lecture: Implementation of Binary Tree

Overview

• This lecture covers how to implement a binary tree.
• Previous knowledge: types, properties, and representation of binary trees.
• Focus: Writing and executing the code for binary tree implementation.

Binary Tree Basics

• Each node contains at most two children (0, 1, or 2).
• Nodes have three parts:
  • Data part
  • Left link (pointer)
  • Right link (pointer)
• Representation: Example with null pointers for no children.

Memory Allocation

• Memory is dynamically allocated for nodes.
• Use a root pointer to access tree nodes, similar to a head pointer in linked lists.
• Define node structure with struct node:
  • Data part (integer)
  • Left and Right pointers (references to child nodes)

Code Implementation

Defining Node Structure

• Define our own data type with struct node which includes:
  • Data
  • Left and Right pointers

Main Function

• Call the create function to build the tree.
• Root pointer (struct node *root) stores the tree's base address.*

Create Function

• Data type: struct node * (returns a pointer to a node).
• Use dynamic memory allocation (C: malloc, C++: new keyword).
• Input value management with printf/scanf.
• Base condition for recursion: enter -1 when no further node is needed (returns null).*

Recursive Creation

• Use recursion to create nodes and link them:
  • Each function call creates a new node.
  • Store data and recursively link left and right children.
• Memory stack: Each function call has its own local variables and execution stack.

Handling Recursion

• Recursive calls create multiple copies of local variables.
• Memory is managed using a stack for function calls.
• Base condition (x == -1) leads to returning null, breaking recursion.

Additional Considerations

• If a node's data is -1, the creation function returns null.
• Use in-order, pre-order, and post-order traversals to verify tree structure.
• Upcoming video will cover tree traversals and related code in detail.

Conclusion

• Understanding recursion and memory allocation is crucial for implementing binary trees.
• Further reading recommended on recursion and its memory allocation.

Note: Next session will cover tree traversal methods and related coding techniques.