Data Structure - Interview Questions and Answers for 'Data structure' | Search Java Interview Question

Data Structure - Interview Questions and Answers for 'Data structure' - 55 question(s) found - Order By Newest

Frequently asked.

Q1. If you are given a choice to use either ArrayList and LinkedList, Which one would you use and Why ?

Core Java

^{Admin
info@buggybread.com}

Ans. ArrayList are implemented in memory as arrays and hence allows fast retrieval through indices but are costly if new elements are to be inserted in between other elements. LinkedList allows for constant-time insertions or removals using iterators, but only sequential access of elements

1. Retrieval - If Elements are to be retrieved sequentially only, Linked List is preferred.

2. Insertion - If new Elements are to be inserted in between other elements , Linked List is preferred.

3. Search - Binary Search and other optimized way of searching is not possible on Linked List.

4. Sorting - Initial sorting could be pain but lateral addition of elements in a sorted list is good with linked list.

5. Adding Elements - If sufficiently large elements needs to be added very frequently ,Linked List is preferable as elements don't need consecutive memory location.

Sample Code for ArrayList

Sample Code for LinkedList

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections list arraylist linkedlist difference between architecture data structure ebay ADP basic frequent}

Try 2 Question(s) Test

Very frequently asked. Favorite question in Walk in Drive of many Indian service companies.

Q2. What is the difference between ArrayList and LinkedList ?

Core Java

^{admin
info@buggybread.com}

Ans. Underlying data structure for ArrayList is Array whereas LinkedList is the linked list and hence have following differences -

1. ArrayList needs continuous memory locations and hence need to be moved to a bigger space if new elements are to be added to a filled array which is not required for LinkedList.

2. Removal and Insertion at specific place in ArrayList requires moving all elements and hence leads to O(n) insertions and removal whereas its constant O(1) for LinkedList.

3. Random access using index in ArrayList is faster than LinkedList which requires traversing the complete list through references.

4. Though Linear Search takes Similar Time for both, Binary Search using LinkedList requires creating new Model called Binary Search Tree which is slower but offers constant time insertion and deletion.

5. For a set of integers you want to sort using quicksort, it's probably faster to use an array; for a set of large structures you want to sort using selection sort, a linked list will be faster.

Sample Code for ArrayList

Sample Code for LinkedList

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve collections java data structures arraylist linkedlist Deutsche Bank Overstock.com HCL Technologies Infosys EBay The Advisory Board Company Accuity JC Penney Cerner Chase Amazon Deloitte Deegit Tata Consultancy Cognizant (CTS) IBM Accenture Mindtree ESRI QwikCilver Solutions TMC Bonds GumGum EMC Yelp Classteacher Learning System FactSet Simply Hired SalesForce Royall & Company Indeed eClinicalWorks TravelClick State Farm Manhattan Associates GoEuro Veeva Systems Ness Technologies Marlabs Rolta Volante Technologies Happiest Minds Technologies Coviam Velocify zanox SimplyHired IDBI Intech Wissen Infotech Nike OnDot PexSupply Pramati Technologies Credit Agricole Mastek Six Dee Telecom Accuity Kellton Tech conduent citrix NEC Technologies Basic frequent}

Try 1 Question(s) Test

Advanced level question frequently asked in US based companies. Recently asked in EMC and Intuit.

Q3. Can you provide some implementation of a Dictionary having large number of words ?

Solution

^{Admin
info@buggybread.com}

Ans. Simplest implementation we can have is a List wherein we can place ordered words and hence can perform Binary Search.

Other implementation with better search performance is to use HashMap with key as first character of the word and value as a LinkedList.

Further level up, we can have linked Hashmaps like ,

hashmap {
a ( key ) -> hashmap (key-aa , value (hashmap(key-aaa,value)
b ( key ) -> hashmap (key-ba , value (hashmap(key-baa,value)
....................................................................................
z( key ) -> hashmap (key-za , value (hashmap(key-zaa,value)
}

upto n levels ( where n is the average size of the word in dictionary.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections hashmap binary search search algorithm advanced architecture data structure Dell EMC Intuit Corporate Brokers PWC India Yahoo Oracle frequent}

Try 1 Question(s) Test

Q4. In a Linked list with sorted numbers, insert a new numbers while maintaining the sort order.

Algorithm

^{2017-07-25 14:59:01}

Ans.
public class LinkedList {

   Node start = null;
   Node head = null;

   class Node{
      Integer body;
      Node nextNode;

      Node(Integer value){
         body = value;
      }
   }

   private void insertInMiddle(Integer value){
      head = start;
      if(start == null) {
         start = new Node(value);
         head = start;
         head.nextNode = null;
         return;
      }

      while(head.body < value){
         if(head.nextNode == null || head.nextNode.body >= value){
            Node newNode = new Node(value);
            newNode.nextNode = head.nextNode;
            head.nextNode = newNode;

            break;
         }
         head = head.nextNode;
      }
   }

   private void traverse(){
      head = start;
      while(head != null){
         System.out.println(head.body);
         head = head.nextNode;
      }
   }

   public static void main(String[] args){
      LinkedList ll = new LinkedList();

      ll.insertInMiddle(5);
      ll.insertInMiddle(10);
      ll.insertInMiddle(15);
      ll.insertInMiddle(7);

      ll.traverse();

   }
}

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve LinkedList Data structures Algorithm}

Q5. Find the third last element in a linked list ?

Search Interview Questions

Help us and Others Improve. Please let us know the questions asked in any of your previous interview.