Algorithms And Data Structures Interview Questions

What Operations Can Be Performed On Queues

• enqueue adds an element to the end of the queue
• dequeue removes an element from the front of the queue
• init is used for initializing the queue
• isEmpty tests for whether or not the queue is empty
• The front is used to get the value of the first data item but does not remove it
• The rear is used to get the last item from a queue

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How Do Signed And Unsigned Numbers Affect Memory

In the case of signed numbers, the first bit is used to indicate whether positive or negative, which leaves you with one bit short. With unsigned numbers, you have all bits available for that number. The effect is best seen in the number range (an unsigned 8-bit number has a range 0-255, while the 8-bit signed number has a range -128 to +127.

What Is Infix Prefix And Postfix In Data Structure

The way to write arithmetic expressions is known as notation. There are three types of notations used in an arithmetic expression, i.e., without changing the essence or output of expression. These notations are:

• Prefix Notation – In this, the operator is prefixed to operands, i.e. ahead of operands.
• Infix Notation – In this, operators are used in between operands.
• Postfix Notation – In this, the operator is postfixed to the operands, i.e., after the operands.

The following table briefly tries to show the difference in all three notations

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What Is Array Data Structure What Are The Applications Of Arrays

An array data structure is a data structure that is used to store data in a way that is efficient and easy to access. It is similar to a list in that it stores data in a sequence. However, an array data structure differs from a list in that it can hold much more data than a list can. An array data structure is created by combining several arrays together. Each array is then given a unique identifier, and each arrays data is stored in the order in which they are created.

Array data structures are commonly used in databases and other computer systems to store large amounts of data efficiently. They are also useful for storing information that is frequently accessed, such as large amounts of text or images.

What Are Some Examples Of Divide And Conquer Algorithms

Quicksort is the name of a sorting algorithm. The method selects a pivot element and rearranges the array elements so that all items less than the pivot chosen element go to the left side of the pivot and all elements more significant than the pivot element move to the right side.

Merge Sort is a sorting algorithm as well. The algorithm divides the array into two halves, sorts them recursively, and then combines the two sorted halves. The goal of points that are closest together is to identify the nearest pair of points in an x-y plane collection of points. The issue may be solved in O time by computing the distances between each pair of locations and comparing them to determine the shortest distance.

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The Intuitive Guide Todata Structures Andalgorithms

This is not a freaking textbook.No confusing academic jargon. No long lists of properties to memorize. No proofs.Because that stuff doesnt help you actually get it.

Heres what does: Learning what to picture in your head when you think of a dynamic array or a hash map. Learning how to think in algorithms.

Thats what this guide is focused ongiving you a visual, intuitive sense for how data structures and algorithms actually work.

So if youve got a big coding interview coming up, or you never learned data structures and algorithms in school, or you did but youre kinda hazy on how some of this stuff fits together

This guide will fill in the gaps in your knowledge and make you say, Oooh, thats how that works.

Well walk you through it all, step by step. Starting from the beginning.

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What Do You Mean By Queue Can You Explain Its Applications

A queue is a data structure which follows the First In First Out logic for operations, which means that the first element input into the queue is operated on first.

A scheduling system is a good example of an application of a queue. Imagine a computing environment where CPU resources are being shared by multiple people. In that case, the work that they want to do can be placed in a queue, with the commands that came first being executed by the queue first.

Java Algorithms Interview Questions For Experienced Developers

Here are some more frequently asked Java algorithms interview questions for experienced developers to help you be sure of your interview preparation:

Q1. How would you find:

• The middle element of a linked list in one pass
• If a linked list has a loop
• The third element from the end in a linked list in one pass
• The one duplicate number in an array that is supposed to have numbers from 1 to 100
• If a number is a palindrome
• The duplicate characters in a string
• The first non-repeated character in a string
• All the substrings of a string in Java
• Length of a String without using any inbuilt method in java
• The level of a node in a binary tree
• The lowest common ancestor in a binary tree
• An element in a sorted array using binary search

Q2. How would you:

• Reverse a linked list using recursion and iteration
• Implement a stack in Java
• Reverse a string

Q11. Implement the following algorithms in Java:

• Dijkstra algorithm
• Kruskalâs algorithm

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What Are The Applications Of Graph Data Structures

Graphs can be used in many different scenarios. That includes:

• In map applications, where the intersection of two roads is designated as a node
• Social media applications conceptualize networks of users by assigning each user as a node and their friends as the nodes that they are connected to.
• The Internet can be visualized in terms of a graph, where each page that links to another page has an edge that connects to it in the graph.

List Some Applications Of Queue Data Structure

To prioritize jobs as in the following scenarios:

• As waiting lists for a single shared resource in a printer, CPU, call center systems, or image uploads where the first one entered is the first to be processed
• In the asynchronous transfer of data or example pipes, file IO, and sockets
• As buffers in applications like MP3 media players and CD players
• To maintain the playlist in media players

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In What Areas Do Data Structures Are Applied

Data structures are essential in almost every aspect where data is involved. In general, algorithms that involve efficient data structure is applied in the following areas: numerical analysis, operating system, A.I., compiler design, database management, graphics, and statistical analysis, to name a few.

Array Coding And Data Structures Interview Questions

An array is the most fundamental data structure, which stores elements at a contiguous memory location. It is also one of the darling topics of interviewers and you will hear a lot of questions about an array in any coding interview, e.g. reversing an array, sorting the array, or searching elements on the array.

The key benefit of an array data structure is that it offers fast O search if you know the index, but adding and removing an element from an array is slow because you cannot change the size of the array once its created.

In order to create a shorter or longer array, you need to create a new array and copy all elements from old to new.

The key to solving array-based questions is having a good knowledge of array data structure as well as basic programming constructors such as loop, recursion, and fundamental operators.

Here are some of the popular array-based coding interview questions for your practice:

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What Are Binary Trees

A binary tree is a tree data structure made up of nodes, each of which has two offspring, known as the left and right nodes. The tree begins with a single node called the root.

Each node in the tree carries the following information:

Data

A pointing device indicates the left kid.

An arrow pointing to the correct child

What Are The Applications Of Doubly Linked Lists

Any application where you require quick forward and backward navigation can employ doubly linked lists. Some examples include:

• The actions that youve taken in an image editing app can be stored in a doubly linked list to allow for each undo/redo operation.
• More complex data structures like binary trees and hash tables can be constructed using doubly linked lists.
• Search engine results pages can be linked to each other using doubly linked lists.

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Trees And Graphs Interview Questions

A tree is usually defined as a collection of nodes. A Graph is a non-linear data structure consisting of a set of objects called vertices or nodes and Edges.

Here is a list of some questions from this topic.

What Are Tree Traversals

Tree traversal is the process of visiting all the nodes of a tree. Since the root is the first node and all nodes are connected via edges we always start with that node. There are three ways which we use to traverse a tree

1. Inorder Traversal:

• Postorder traversal is commonly used to delete the tree.
• It is also useful to get the postfix expression of an expression tree.

Consider the following tree as an example, then:

• Inorder Traversal => Left, Root, Right :
• Preorder Traversal => Root, Left, Right :
• Postorder Traversal => Left, Right, Root :

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What Are The Differences Between The B Tree And The B+ Tree

The B tree is a self-balancing m-way tree, with m defining the tree’s order. Depending on the number of m, Btree is an extension of the Binary Search tree in which a node can have more than one key and more than two children. The data is provided in the B tree in a sorted manner, with lower values on the left subtree and higher values on the right subtree.

The B+ tree is an advanced self-balanced tree since every path from the tree’s root to its leaf is the same length. The fact that all leaf nodes are the same length indicates that they all occur at the same level. Specific leaf nodes cant appear at the third level, while others appear at the second level.

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C# Data Structure Interview Questions About Processes

Ask your candidates some of these nine C# data structure interview questions about processes to learn more about how they approach challenges with C#.

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Java Algorithms Interview Questions And Answers

Letâs take a look at some popular Java algorithms interview questions that you can practice for your tech interview:

Q1. What are the different types of tree traversal algorithms?

There are broadly four types of tree traversals, and each type has algorithms that help us achieve that type of traversal. The four types are inorder traversal, preorder traversal, postorder traversal, and level order traversal.

Q2. What are some of the most used sorting algorithms?

This is a commonly asked Java algorithms interview question. It tests your basic conceptual knowledge. Hereâs how you can answer this: Quicksort, merge sort, heap sort, and insertion sort are some of the most used sorting algorithms.

Q3. What are some examples of greedy algorithms?

Travelling Salesman problem, Knapsack problem, job scheduling problem, Prim’s, Kruskal’s, and Dijkstra’s Minimum Spanning Tree algorithms, Map coloring in Graphs, and Vertex cover in graphs are some examples that utilize greedy algorithms.

Q4. Give some examples of divide and conquer algorithms.

Binary Search, Merge Sort, Quick Sort, and Strassen’s Matrix Multiplication are some examples of divide and conquer algorithms.

Q5. What is the fastest searching algorithm?

Binary search is usually the fastest searching algorithm and is most widely used for efficient searching as well.

Can You Explain With An Example How Does A Variable Declaration Activity Will Consume Or Affect The Memory Allocation

The amount of space or memory is occupied or allocated depends upon the data type of the variables that are declared. So lets explain the same by considering an example: Lets say the variable is declared as an integer type then 32 bits of memory storage is allocated for that particular variable.

So based on the data type of the variable, the memory space will be allocated.

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Explain What Is Merge Sort And How It Is Useful

A merge sort is nothing but a process where the data is divided and sorted to reach the end goal. Within this process, the adjacent elements are merged and sorted to create bigger elements. These sorted elements are gathered again and made the even bigger list. This process is continuous and repetitive until and unless they have nailed it down to a single sorted list.

Cracking The Coding Interview: 189 Programming Questions And Solutions

Gayle Laakmann McDowellDescription: This book is currently the no.1 bestseller in data structures and algorithms on Amazon. This impressive book includes

• 189 programming interview questions, ranging from the basics to the trickiest algorithm problems and their solutions.
• Extensive coverage of essential topics, such as big O time, data structures, and core algorithms.
• Five proven strategies to tackle algorithm questions, so that you can solve questions you havent seen.
• Techniques to prepare for and ace the soft side of the interview: behavioral questions.

After going through this book, there are high chances that you will ace your next coding interview.

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How Are The Elements Of A 2d Array Are Stored In The Memory

There are two techniques by using which, the elements of a 2D array can be stored in the memory.

• Row-Major Order: In row-major ordering, all the rows of the 2D array are stored into the memory contiguously. First, the 1st row of the array is stored into the memory completely, then the 2nd row of the array is stored into the memory completely and so on till the last row.
• Column-Major Order: In column-major ordering, all the columns of the 2D array are stored into the memory contiguously. first, the 1st column of the array is stored into the memory completely, then the 2nd row of the array is stored into the memory completely and so on till the last column of the array.

What Is A Bubble Sort And How Do You Perform It

A bubble sort is one sorting technique that can be applied to data structures such as an array. It works by comparing adjacent elements and exchanges their values if they are out of order. This method lets the smaller values bubble to the top of the list, while the larger value sinks to the bottom.

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Write A Function To Implement Quicksort On Doubly Linked List

• Input: 8< -> 10< -> 1< -> 7< -> 6
• Output: 1< -> 6< -> 7< -> 8< -> 10

class Solution              tt = tt ->  next         }        swap         return first     }} void _quickSort}void quickSort

• Time Complexity: O in the worst case when the list is already sorted. O) in the best and average case.
• Space Complexity: O