How To Recognize When To Use A Tree
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 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:
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
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.
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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:
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:
The Top Data Structures You Should Know For Your Next Coding Interview
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:
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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
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.
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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
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:
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
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:
- Data Structures and Algorithms: Deep Dive Using Java for Java developers. Learn about Arrays, Linked Lists, Trees, Hashtables, Stacks, Queues, Heaps, Sort algorithms, and Search algorithms
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.