Data Structures

• Definition: A stack is a collection of elements with two main operations: push (adding an element) and pop (removing the most recently added element).
• Characteristics:
  • LIFO (Last In, First Out): The last element added is the first one to be removed.
  • Operations:
    • Push: Adds an element to the top of the stack.
    • Pop: Removes the top element from the stack.
    • Peek/Top: Returns the top element without removing it.

• Definition: A queue is a collection of elements with two main operations: enqueue (adding an element) and dequeue (removing the earliest added element).
• Characteristics:
  • FIFO (First In, First Out): The first element added is the first one to be removed.
  • Operations:
    • Enqueue: Adds an element to the end of the queue.
    • Dequeue: Removes the front element from the queue.
    • Front/Peek: Returns the front element without removing it.

Example:

• Usage: Managing tasks in a printer queue where the first task submitted is the first one to be printed.

• Definition: A tree is a hierarchical data structure consisting of nodes, with each node having zero or more child nodes.
• Characteristics:
  • Root: The top node in a tree.
  • Child: A node directly connected to another node when moving away from the root.
  • Leaf: A node with no children.
  • Subtree: A tree consisting of a node and its descendants.

Example:

• Usage: Representing hierarchical data such as file systems or organisational structures.

Types of Trees:

• Binary Tree: Each node has at most two children.
• Binary Search Tree (BST): A binary tree where the left child contains values less than the parent node and the right child contains values greater than the parent node.
• Balanced Trees: Trees like AVL trees or Red-Black trees that maintain a balanced height to ensure efficient operations.

Binary Tree: