Polestar Solutions & Services India 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.

• For...read more

Recursion is a process in which a function calls itself. Inheritance is a mechanism in OOP where a class inherits properties of another class. Heap is a region of memory used for dynamic memory allocation.

• Recursion can be used to solve problems that can be broken down into smaller sub-problems.

• Inheritance allows for code reuse and helps in creating a hierarchy of classes.

• Heap is used for dynamic memory allocation in la...read more