BT Group Associate Data Engineer Interview Questions and Answers

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.

• Start from the first element and compare it with the next element

• If the next element is smaller, swap them

• Repeat this process for all elements in the array

• Continue this process until no more swaps are needed

A program to print all prime numbers

• Take input from user for range of numbers

• Loop through the range and check if each number is prime

• Print the prime numbers

Hashmap is a data structure that stores key-value pairs and allows constant time access to values based on their keys.

• Hashmap uses a hash function to map keys to indices in an array.

• Collisions can occur when multiple keys map to the same index, which can be resolved using techniques like chaining or open addressing.

• Examples of hashmap implementations include Java's HashMap class and Python's dict type.

Inheritance is a mechanism in object-oriented programming where a new class is created by inheriting properties of an existing class.

• Inheritance allows code reuse and promotes code organization.

• The existing class is called the parent or superclass, and the new class is called the child or subclass.

• The child class inherits all the properties and methods of the parent class and can also add new properties and methods.

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OOPs concepts are the fundamental principles of object-oriented programming.

• Encapsulation - binding data and functions that manipulate the data

• Inheritance - creating new classes from existing ones

• Polymorphism - ability of objects to take on many forms

• Abstraction - hiding implementation details and showing only functionality

Storage classes in C define the scope and lifetime of variables.

• There are four storage classes in C: auto, register, static, and extern.

• Auto variables are local to a block and have automatic storage duration.

• Register variables are stored in CPU registers for faster access.

• Static variables have a lifetime throughout the program and are initialized only once.

• Extern variables are declared outside any function and can be a