DSA Introduction : MCQs & PYQs with Explanation

Option D

A data structure is particular way of storing and organizing data in computer system. So that it can be used efficiently.

Option A

Option A

Data structure is way of storing and organizing data in a computer so that it can be used efficiently. For example, dictionary is good example of organized data in which the words are arranged in a particular order.

Option B

Data structures are classified as linear and non-linear based on how elements are arranged. 
In non-linear data structures, elements are not arranged sequentially, instead, they have Hierarchical or Network relationships. 
A Graph consists of nodes (vertices) connected by edges and does not follow a linear sequence, so it is a non-linear data structure.

Option A

Random access means accessing any element directly using its index without traversing other elements. 
An Array is best suited for this because it stores elements in contiguous memory locations, allowing direct access using an index as arr[i]. This makes access very fast with constant time complexity O(1).

Option B

Recursion is a technique where a function calls itself to solve smaller versions of the same problem until reaching a simple base case that stops the calls.
When a function calls itself, the computer must remember the current state of the function before jumping to the next call. To manage these multiple pending function calls, the system uses a stack.
Each time a function is called, a stack frame is pushed onto the stack, and when the function returns, the stack frame is popped.

Option B

Big-O notation is used to describe how fast an algorithm grows in terms of its input size (n). It helps us understand the worst-case (upper bound) performance of an algorithm.

Option D

A Data Structure is a way of storing and organizing data in computer system so that it can be used efficiently. Different data structures are used depending on what operations we need. Choosing the right data structure makes programs faster and easier to manage.

In a Linear data structure, elements are arranged one after another in a sequence. Each element has a unique predecessor and unique successor, except the first and last elements. Array, Stack, Queue, Linked List are example of linear data structure.
In a Non-Linear data structure, elements are not arranged sequentially. An element can connect to multiple elements, forming structures like hierarchical or networks. Tree and Graph are example of non-linear data structure.

Option C

An Abstract Data Type (ADT) is a data type that is defined by the set of operations that can be performed on it, not by how it is implemented. 
Users of an ADT can only use the operations specified in its definition, while the internal representation and implementation details are hidden.

• An ADT is a model for a data structure that defines data (variables) and operations (functions) but without implementation.
• It focuses on what you can do, not how it is done.

Option B

In computer science, data structures are classified into Linear and Non-Linear. Linear data structures arrange elements sequentially, where each element has a unique predecessor and successor (except the first and last) such as arrays, stacks, queues, and linked lists.

Non-Linear data structures do not follow this sequential order and allow for hierarchical or networked connections. In this one element can connect to multiple elements. Examples of non-linear data structure are Tree (hierarchical structure, parent-child relationships) and Graph (elements connected arbitrarily).