Sunday, March 17, 2024

Data Structures For Coding Interviews In Java

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How To Recognize When To Use A Tree

Data Structures Interview Questions | Data Structures And Algorithms | Java Training | Edureka

Most of the time, tree problems will be explicitly stated as such. The problem will come in the form of Given a tree, do X.

The most important thing when you see problems like this is to make sure that you understand what type of tree youre dealing with. If its a BST, that has different implications than if its just a binary tree that is not sorted.

The two other possible cases where youll use trees in problems are:

  • Storing data in a BST
  • Using a Trie to find string prefixes
  • Storing data in a BST is something that we may occasionally want to do, although its not usually the most efficient option. If you end up doing this, youll probably want to use a built in tree structure rather than implementing your own, since that will provide additional benefits like rebalancing.

    If youre trying to find strings by their prefix, then tries are inherently a great way to do that. For example, if you wanted to implement an autocomplete tool, tries would be a good option.

    What Can I Achieve From The Purdue Postgraduate Data Science Program

    You will receive the following as part of this PG in Data Science, which is offered in conjunction with IBM:

  • Simplilearn-Purdue university Joint Certification
  • Industry recognized certificates from IBM and Simplilearn
  • Purdue Alumni Association membership
  • Lifetime access to all of the e-learning content created by Simplilearn
  • Access to IBM Cloud platforms featuring IBM Watson and other cloud services
  • What Are Asymptotic Notations

    Asymptotic Notation represents an algorithmâs running time â how long an algorithm takes with a given input, n. Big O, large Theta , and big Omega are the three distinct notations. When the running time is the same in all circumstances, big- is used, big-O for the worst-case running time, and big- for the best case running time.

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    How To Implement A Queue Using Stack

    A queue can be implemented using two stacks. Let q be the queue andstack1 and stack2 be the 2 stacks for implementing q. We know that stack supports push, pop, and peek operations and using these operations, we need to emulate the operations of the queue – enqueue and dequeue. Hence, queue q can be implemented in two methods ):

    1. By making enqueue operation costly:

    • Here, the oldest element is always at the top of stack1 which ensures dequeue operation occurs in O time complexity.
    • To place the element at top of stack1, stack2 is used.
    • Enqueue: Here time complexity will be O
    enqueue:  While stack1 is not empty:     Push everything from stack1 to stack2.      Push data to stack1      Push everything back to stack1.
    • Dequeue: Here time complexity will be O
    deQueue: If stack1 is empty then error  else Pop an item from stack1 and return it

    2. By making the dequeue operation costly:

    • Here, for enqueue operation, the new element is pushed at the top of stack1. Here, the enqueue operation time complexity is O.
    • In dequeue, if stack2 is empty, all elements from stack1 are moved to stack2 and top of stack2 is the result. Basically, reversing the list by pushing to a stack and returning the first enqueued element. This operation of pushing all elements to a new stack takes O complexity.
    enqueue:    Push data to stack1
    • Dequeue: Time complexity: O

    Top 100 Coding Problems From Programming Job Interviews

    Data Structure and algorithm interview questions in java

    Without wasting any more of your time, here is my list of 100 frequently asked coding problems from programming job interviews. In order to get most of this list, I suggest actually solving the problem.

    Do it yourself, no matter whether you are stuck because thats the only way to learn. After solving a couple of problems you will gain confidence.

    I also suggest you look at the solution when you are stuck or after you have solved the problem, this way you learn to compare different solutions and how to approach a problem from a different angle.

  • How is a bubble sort algorithm implemented?
  • How is a merge sort algorithm implemented?
  • How do you count the occurrence of a given character in a string?
  • How do you print the first non-repeated character from a string?
  • How do you convert a given String into int like the atoi?
  • How do you implement a bucket sort algorithm?
  • How do you implement a counting sort algorithm?
  • How do you remove duplicates from an array in place?
  • How do you reverse an array in place in Java?
  • How are duplicates removed from an array without using any library?
  • How is a radix sort algorithm implemented?
  • How do you swap two numbers without using the third variable?
  • How do you check if two rectangles overlap with each other?
  • How do you design a vending machine?
  • How do you find the missing number in a given integer array of 1 to 100?
  • How do you find the duplicate number on a given integer array?
  • Difference between a stable and unstable sorting algorithm?
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    Crack The Top 50 Java Data Structure Interview Questions

    Java remains one of the most popular languages around the world, especially in financial fields. Companies like Goldman Sachs, eBay, , and Microsoft all hire Java developers.

    Today, well help you prepare for your next job interview at these and other popular companies by reviewing 50 of the most common Java data structure interview questions and answers.

    Heres what well look at today:

    Commonly Asked Data Structure Interview Questions

    What is a Data Structure? A data structure is a way of organizing data so that the data can be used efficiently. Different kinds of data structures are suited to different kinds of applications, and some are highly specialized for specific tasks. For example, B-trees are particularly well-suited for the implementation of databases, while compiler implementations usually use hash tables to look up identifiers.

    What are linear and non-linear data Structures?

    • Linear: A data structure is said to be linear if its elements form a sequence or a linear list. Examples: Array. Linked List, Stacks and Queues
    • Non-Linear: A data structure is said to be non-linear if the traversal of nodes is nonlinear in nature. Example: Graph and Trees.

    What are the various operations that can be performed on different Data Structures?

    • Insertion ? Add a new data item in the given collection of data items.
    • Deletion ? Delete an existing data item from the given collection of data items.
    • Traversal ? Access each data item exactly once so that it can be processed.
    • Searching ? Find out the location of the data item if it exists in the given collection of data items.
    • Sorting ? Arranging the data items in some order i.e. in ascending or descending order in case of numerical data and in dictionary order in case of alphanumeric data.

    Applications of Stack:

  • Check for balanced parentheses in an expression
  • What are Infix, prefix, Postfix notations?

       A *  / D
       A B C + * D/

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    Which Programming Language To Use For Coding Interviews

    Does the programming language you use for coding interviews matter? The answer is yes.

    Most companies let you code in any language you want – the only exception I know being Google, where they only allow candidates to pick from Java, C++, JavaScript or Python for their algorithmic coding interviews.

    However, the choice you make can impact your performance much more than you’d like to believe – and this is why it is important to pick a suitable programming language early on in your coding interview preparation – and use regularly in practice.

    There are 3 considerations when deciding on which programming language to use:

  • Suitability for interviews
  • Your familiarity with the language
  • The Top Data Structures You Should Know For Your Next Coding Interview

    Top 6 Coding Interview Concepts (Data Structures & Algorithms)

    Niklaus Wirth, a Swiss computer scientist, wrote a book in 1976 titled Algorithms + Data Structures = Programs.

    40+ years later, that equation still holds true. Thats why software engineering candidates have to demonstrate their understanding of data structures along with their applications.

    Almost all problems require the candidate to demonstrate a deep understanding of data structures. It doesnt matter whether you have just graduated , or you have decades of experience.

    Sometimes interview questions explicitly mention a data structure, for example, given a binary tree. Other times its implicit, like we want to track the number of books associated with each author.

    Learning data structures is essential even if youre just trying to get better at your current job. Lets start with understanding the basics.

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    Data Structures And Algorithm Interview Questions For Java Programmers

    Question 1: How to find the middle element of the linked list in one pass?find the middle element of the linked list in a single passQuestion 2: How to find if a linked list has a loop?linked list with cyclesQuestion 3: How to find the third element from the end in a linked list in one pass?Algorithms and Data Structures Part 1 and 2 coursesQuestion 4: In an integer array, there is 1 to 100 number, out of one is duplicate, how to find?find a duplicate number in the arrayQuestion 5: How to reverse String in Java?3 ways to reverse String in Javarecursion in JavaQuestion 6: Write a Java program to sort an array using the Bubble Sort algorithm?How to sort an array using Bubble Sort in JavaQuestion 7: What is the difference between Stack and Queue data structure?stack vs queueQuestion 8: How do you find duplicates in an array if there is more than one duplicate? Hashtable or HashMapHashMapQuestion 9: What is the difference between the Singly Linked List and Doubly Linked List data structure?Grokking the Coding Interview: Patterns for Coding Questions courseQuestion 10: Write a Java program to print the Fibonacci series?find the nth Fibonacci number in JavaQuestion 11: Write a Java program to check if a number is a palindrome or not? Java program to check if the number is palindrome or notQuestion 12: What is a binary search tree? in orderpreorderpostorder Question 13: How to reverse a linked list using recursion and iteration? solution P. S.

    What Is The Eligibility Criteria For This Data Science Certification

    ThisData Science certification requires the following qualifications:

  • A bachelor’s degree with a 50% or above grade point average.
  • Understanding basic programming principles and mathematics is required.
  • Working professionals with at least two years of experience are recommended for this Data Science Certification Program.
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    The Definitive Guide To Data Structures For Coding Interviews

    If youve been reading Byte by Byte for any length of time, then you know that I have one mantra that I repeat over and over again:

    Strategy, Strategy, Strategy

    This is the one biggest difference between those students who succeed and those who fail at their coding interview. Its not who has studied the most problems. Its not who grinds the most Leetcode. Its not who is naturally the smartest.

    The biggest difference is having a strategy for solving ANY problem, not just the ones youve seen before. And this approach is why our students see such fantastic results.

    But

    Heres the thing about strategy: Without the proper building blocks in place, youll never succeed. Thats why Data Structures are so key.

    Trying to nail a coding interview without having your Data Structures down cold is like trying to play basketball without knowing how to dribble. All the strategy in the world wont help you be successful.

    So in this post, Im going to share with you ALL of the data structures and algorithms that you need to be successful in your coding interviews.

    Best Tips To Crack Coding Interviews In 2022

    Coding: [Java] Java Interview Questions 08/14

    Here are a few of my practical tips to crack your next coding interview. These are hard-earned and I learned from my own mistakes and experience.

  • There is no better way to do well in Coding interviews than practicing as many coding problems as possible. This will not only train your mind to recognize algorithmic patterns in problems but also give you the much-needed confidence to solve problems you have never seen before.
  • My second tips are to learn about as many data structure and algorithms as possible. This is an extension of the previous tip but it also involves reading and not just practicing. For example, If you know about the hash table you can also many array and counter-based problems easily. The same is true for trees and graphs.
  • Choosing the right data structure is a very important part of software development and coding interview and unless and until you know them, you wont be able to choose.
  • Time yourself candidates who solve interview problems within the time limit and quickly are more likely to do well in the interview so you should also time yourself.
  • Think of edge cases and run your code through them. Some good edge cases might be the empty input, some weird input, or some really large input to test the boundary conditions and limits.
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    Algorithms Data Structures In Java #1

    • grasp the fundamentals of algorithms and data structures
    • detect non-optimal code snippets
    • learn about arrays and linked lists
    • learn about stacks and queues
    • learn about binary search trees
    • learn about balanced binary search trees such as AVL trees or red-black trees
    • learn about priority queues and heaps
    • learn about B-trees and external memory
    • learn about hashing and hash tables

    Java Data Structures Interview Questions On Arrays

  • For a given unsorted array, write a program to find a contiguous subarray that adds to a given number in the array
  • For two unsorted arrays where elements are in non-decreasing order, write a code to merge the two arrays such that the new array is sorted
  • For a given array of size N-1, containing integers in the range from 1 to N, write a program to find the missing element in the array
  • For a given array containing positive integers, write a code to return the sum of the elements of the array
  • For a given unsorted array of size N, write a code to rotate it anticlockwise, by D elements
  • For a given array of size N, write a code to print the reverse of the array
  • For a given array A, write a code to delete the duplicate elements in the array
  • For a given array Arr containing integer elements, write a code to find the minimum and maximum elements of the array
  • For a given array of size N containing distinct integer numbers, write a code to sort the array in the wave fashion
  • From a given array containing integer values, write a code to find the maximum subarray of non-negative numbers
  • Take a look at the Concept of Arrays in Java Data Structures here.

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    Tips For Cracking The Google Software Engineer Interview

    Before going in, ensure that you keep the following in mind and put your best efforts into clearing the Google software engineer interview:

  • Have a thorough understanding of the work culture at Google because a good part of the interview process is focused on determining whether youâre a cultural fit for the company or not.
  • Practice data structures and algorithms questions and work on developing your knowledge. Google looks for problem solvers, so the quicker you are, the higher are your chances of getting selected.
  • When preparing for Google software engineer interview questions, use the STAR method . Start by describing the situation, the task you did, the action you took in response to the given task, and finally, explain your experience and the result.
  • Donât keep your strengths to yourself. Be bold and confidently describe your strengths using your past experiences. Even if you are answering a question where you have to describe a mistake youâve made in the past, be clear and own up to it.
  • Make the interviewer feel like theyâre a part of the communication and keep it going.
  • These tips will always come in handy â whether youâre appearing for the Google software engineer intern interview or youâre an experienced professional. You can learn more here.

    If you want some more help, check out these articles:

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    What Is The Difference Between The Breadth First Search And Depth First Search

    Java Data Structures Tutorial
    Breadth First Search
    DFS necessitates less memory.
    Nodes that have been traversed multiple times are removed from the queue. When there are no more nodes to visit, the visited nodes are added to the stack and then removed.
    Backtracking is not an option in BFS. The DFS algorithm is a recursive algorithm that employs the concept of backtracking.
    It is based on the FIFO principle . It is based on the LIFO principle .

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    Best Resources For Coding Interviews

    The selection of good resources is very important for success in your coding interviews. If you chose the wrong resource then more than money, you will lose the valuable time you need for preparation, hence spending some time researching for a good resource.

    If you need recommendations, the following are some of my the tried and tested resources to learn Data Structure and Algorithms in-depth for coding interviews:

    And, if you prefer books, there is no better than the Cracking The Coding Interview, by Gayle Laakmann McDowellwhich presents 189+ Programming questions and solutions. A good book to prepare for programming job interviews in a short time. Btw, I will also earn some money if you buy any of these resources mentioned here.

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