Chapter 3

7.1 Introduction to Data Structures

Data structures are specialized formats for organizing, processing, retrieving, and storing data. They are fundamental to efficient algorithm design and implementation. In computer science, data structures help manage large amounts of data efficiently for uses such as large databases and internet indexing services. The choice of data structure can greatly affect the performance of a program or algorithm. Data structures are broadly classified into primitive and non-primitive types. Primitive data structures include basic types like integers, floats, characters, and pointers. Non-primitive data structures are more complex and include arrays, lists, stacks, queues, trees, and graphs. The selection of an appropriate data structure depends on the type of operation to be performed, such as insertion, deletion, searching, or sorting. Understanding data structures is essential for solving computational problems efficiently and is a foundational concept in the study of algorithms.

• Data structures organize and store data efficiently.
• They are classified into primitive and non-primitive types.
• The choice of data structure affects algorithm performance.
• Non-primitive types include arrays, lists, stacks, queues, trees, and graphs.
• Data structures are essential for efficient data management.
• They are foundational for algorithm design.
• 📌 Data Structure: A way of organizing and storing data for efficient access and modification.
• 📌 Primitive Data Structure: Basic data types such as int, float, char, and pointer.
• 📌 Non-Primitive Data Structure: More complex types like arrays, lists, stacks, and queues.

7.2 Arrays

An array is a collection of elements, all of the same data type, stored in contiguous memory locations. Each element in an array can be accessed directly using its index or position. Arrays are one of the simplest and most commonly used data structures. They are useful for storing data that needs to be accessed in a sequential manner, such as marks of students, daily temperatures, or list of names. The size of an array must be specified at the time of its declaration and cannot be changed during program execution. Arrays can be one-dimensional, two-dimensional, or multi-dimensional. One-dimensional arrays are like lists, while two-dimensional arrays are like tables or matrices. Operations on arrays include traversal, insertion, deletion, searching, and updating elements. Arrays are efficient for accessing elements but can be inefficient for insertion and deletion, especially in the middle of the array.

• Arrays store elements of the same type in contiguous memory.
• Each element is accessed using an index.
• Array size is fixed at declaration.
• Arrays can be one-dimensional or multi-dimensional.
• Common operations include traversal, insertion, deletion, and searching.
• Efficient for accessing elements but not for insertions/deletions in the middle.
• 📌 Array: A collection of elements of the same type stored in contiguous memory.
• 📌 Index: The position of an element in an array, starting from 0.
• 📌 Traversal: Accessing each element of the array sequentially.