Data Structures: Arrays, Linked Lists, Stacks, Trees

Arrays

• A collection of elements of the same data type stored in contiguous memory locations.
• Each element is identified by an index or key.
• Operations:
  • Access: O(1) - Direct access using index.
  • Insert: O(n) - Shifting elements to make space.
  • Delete: O(n) - Shifting elements to fill gap.
• Advantages:
  • Efficient in terms of memory usage.
  • Fast access time.
• Disadvantages:
  • Fixed size, cannot be resized dynamically.
  • Insertion and deletion are costly.

Linked Lists

• A dynamic collection of elements, where each element (node) points to the next node.
• Types:
  • Singly Linked List: Each node points to the next node.
  • Doubly Linked List: Each node points to both the previous and next node.
• Operations:
  • Access: O(n) - Sequential access.
  • Insert: O(1) - Inserting at the beginning or end.
  • Delete: O(1) - Deleting at the beginning or end.
• Advantages:
  • Dynamic size, can be resized easily.
  • Efficient insertion and deletion.
• Disadvantages:
  • More memory usage due to node pointers.
  • Slow search time.

Stacks

• A Last-In-First-Out (LIFO) data structure.
• Operations:
  • Push: Adding an element to the top of the stack.
  • Pop: Removing an element from the top of the stack.
  • Peek: Viewing the top element without removing it.
• Properties:
  • Follows the LIFO principle.
  • Can be implemented using arrays or linked lists.
• Applications:
  • Evaluating postfix expressions.
  • Implementing recursive functions.

Trees

• A hierarchical data structure composed of nodes, where each node has a value and zero or more child nodes.
• Types:
  • Binary Tree: Each node has at most two child nodes.
  • AVL Tree: A self-balancing binary search tree.
  • B-Tree: A self-balancing search tree.
• Operations:
  • Insert: O(log n) - Balanced trees.
  • Search: O(log n) - Balanced trees.
  • Delete: O(log n) - Balanced trees.
• Advantages:
  • Efficient search and insertion operations.
  • Can be used for database indexing.
• Disadvantages:
  • More complex implementation.
  • Can be unbalanced, leading to poor performance.

Understanding the basics of data structures including arrays, linked lists, stacks, and trees. Learn about their operations, advantages, and disadvantages.