Data Structures with C

What are Data Structures?

A data structure is a way of organizing, managing, and storing data so that it can be accessed and modified efficiently. Data structures provide a structured way to store and manage large amounts of data in a program. They determine how data is stored in memory, how it can be retrieved, and how operations like search, insertion, and deletion are performed.

Why are Data Structures Needed?

  1. Efficiency: Data structures allow efficient access to and modification of data, which can improve the performance of algorithms. For example, searching for an element in an array takes linear time, but in a binary search tree, it can take logarithmic time.
  2. Organizing Data: They help organize data in a meaningful way so that it can be used effectively. For example, a stack data structure can be used to manage tasks in the order of “last in, first out.”
  3. Data Management: They help in storing data that can be processed for useful outcomes. For example, a database system uses various data structures to store and manage data efficiently.
  4. Memory Management: Data structures allow for more efficient use of memory. For instance, a linked list allows dynamic memory allocation, unlike arrays that require pre-allocation.

Types of Data Structures

Data structures can be broadly classified into two types:

1. Linear:

In linear data structures, data elements are arranged in a sequence, one after the other.

  • Array:
    • A collection of elements, each identified by an index.
    • Elements are stored in contiguous memory locations.
    • Example: int arr[5] = {1, 2, 3, 4, 5};
  • Linked List:
    • A sequence of elements where each element points to the next element in the sequence.
    • Can grow dynamically and doesn’t need contiguous memory.
    • Example: Singly Linked List, Doubly Linked List.
  • Stack:
    • Follows the “Last In, First Out” (LIFO) principle.
    • Insertion and deletion are performed at the same end.
    • Example: Undo operations in text editors.
  • Queue:
    • Follows the “First In, First Out” (FIFO) principle.
    • Insertion happens at the rear, and deletion happens at the front.
    • Example: Printer queues.
2. Non-Linear:

In non-linear data structures, data elements are not arranged in a sequence. Instead, they are stored in a hierarchical or interconnected way.

  • Tree:
    • A hierarchical structure with nodes.
    • Each node has a parent-child relationship.
    • Example: Binary Tree, Binary Search Tree, AVL Tree.
  • Graph:
    • A collection of nodes connected by edges.
    • Can represent various real-world relationships.
    • Example: Social networks, GPS navigation.
  • Heap:
    • A specialized tree-based structure that satisfies the heap property (either max heap or min heap).
    • Example: Priority queues.
3. Hash-Based:

These structures use a hash function to map data to a fixed-size table.

  • Hash Table:
    • Stores data in key-value pairs.
    • Uses a hash function to compute the index where a value is stored.
    • Example: Dictionaries in Python, HashMap in Java.

In this series of articles, we will explore the creation and management of data structures using the C programming language.

  1. Linear Data structures

Github link for applications on linked lists