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

Data Structure - Interview Questions and Answers for 'Data structure' - 72 question(s) found - Order By Rating

Q1. How to delete a node from linked list if u do not have head and only have a pointer to the element which has to be removed ?

Data Structure

^{2019-11-22 12:22:22}

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Q2. How to sort an ArrayList of objects

Data Structure

^{2019-10-29 15:21:43}

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Q3. What is the O notation for the ArrayList and List? And which one would you choose to insert item in the middle?

Data Structure

^{2019-10-29 15:21:28}

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Q4. What is Queue ?

Data Structure

^{2019-09-23 15:23:45}

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Q5. Write an algorithm to shift a linked list n positions.

Data Structure

^{2019-09-17 13:10:15}

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Q6. What is the time complexity and space complexity of reversing a Linked List ?

Data Structure

^{2019-09-17 09:01:18}

Ans. o(n) for time complexity
o(1) for space complexity

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Q7. What is Message Queue or MQ ?

Data Structure

^{2019-08-30 09:43:33}

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Q8. Linked List related questions.

Data Structure

^{2019-06-17 07:56:25}

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Q9. How to build a blocking queue ?

Data Structure

^{2019-05-31 14:36:56}

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Q10. Implement a queue, using only stacks

Data Structure

^{2019-01-31 20:38:20}

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Q11. Write a Program to print all nodes of the data structure ?

Algorithm

^{2019-01-29 13:24:26}

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Q12. Implement a Stack with 2 threads in which one thread push data and another pop data.

Data Structure

^{2018-11-27 09:14:19}

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Q13. Detect a loop in a linked list

Data Structure

^{2018-11-14 12:48:43}

Ans. Work with two pointers on the linked list - a slow pointer (increments by one node) and a fast pointer (increments by two nodes). If both of these pointers meet at the same node, then there is a cycle in the linked list. Otherwise, no cycle.

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Q14. Write a Program to Find the maximum sum of the sub array ?

Data Structure

^{2018-09-16 16:26:46}

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Q15. Write a program to insert a value after a specific value in an array.

Data Structure

^{2018-07-22 07:39:24}

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Q16. Find the length of the non repeated numbers in an array.

Data Structure

^{2018-07-22 07:35:38}

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Q17. Find number of recycled pairs in n array.

Data Structure

^{2018-07-22 07:33:16}

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Q18. In an array every element is repeated twice except one, Find that element?

Data Structure

^{2018-07-22 07:30:31}

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Q19. Difference between Arrays and LinkedList ?

Data Structure

^{2018-07-22 07:24:14}

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Q20. Can you write code to copy one array into another ?

Data Structure

^{2018-07-22 07:19:26}

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Q21. What is hashing ?

data structure

^{2018-06-25 12:22:40}

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Q22. Why does an array need continuous memory locations and not Linked List ?

Data Structure

^{2018-06-11 09:21:56}

Ans. Array needs continuous memory location because it need to provide random access of it's elements which is not required for Linked List.

Array index acts as an offset from the base address and hence can retrieve the respective element using the expression Base Address + ( Index * Element Size ). This expression could only hold true if the elements are in continuous memory location.

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Q23. Why does an array index starts at 0 and not 1 ?

Data Structure

^{2018-06-11 08:41:24}

Ans. The array index starts with 0 because program locates an element using the expression ( BaseAddress + ( Index * size of array Element ), where index is used as an offset. As the starting address is actually the address of first element, the index of first element is used as 0 and so on.

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Q24. How will you implement your own custom hashmap and linkedlist ?

Data Structure

^{2018-06-08 19:16:25}

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Q25. What can we do if we need to retrieve Fibonacci value at a particular index faster ? Can we use Linked List ?

Data Structure

^{2018-06-05 15:32:51}

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Q26. Write a method that returns maximum depth of a tree ?

Algorithm

^{2018-05-24 08:40:50}

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Q27. What is the difference between pop and peek function of stack ?

Data Structure

^{2018-05-24 08:34:36}

Ans. pop method pulls the top element from the stack and then move the top to the next element whereas peek only get the top element but doesn't move the top.

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Q28. Write a program to sort a stack in ascending order You should not make any assumptions about how the stack is implemented The following are the only functions that should be used to write this program: push | pop | peek | isEmpty

Algorithm

^{2018-05-24 08:33:37}

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Q29. Describe how you could use a single array to implement three stacks

Algorithm

^{2018-05-24 08:28:08}

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Q30. Write a Program to implement stack using LinkedList.

Data Structure

^{2018-05-24 08:25:40}

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Q31. What is the access time for ArrayList and LinkedList ?

Data Structure

^{2018-05-23 19:18:48}

Ans. O(1) for ArrayList
O(n) for LinkedList

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Q32. What is the "multiplicative congruence" method for determining where an element belongs in a hash table ?

Data Structure

^{2018-05-19 18:57:35}

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Q33. Describe how a queue is usually created using sequential allocation.

Data Structure

^{2018-05-19 18:56:18}

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Q34. If a stack is implemented using linkedlist, which end (head or tail) should represent the top ?

Data Structure

^{2018-05-19 18:55:34}

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Q35. If a stack is implemented using an array, which end (head or tail) should represent the top ?

Data Structure

^{2018-05-19 18:54:28}

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Q36. Can we access elements at a particular index using LinkedList collection class ?

Data Structure

^{2018-04-29 09:05:25}

Ans. Yes we can. But as the underlying structure of the collection class is double linked list, it will eventually have to traverse to the element linearlly and hence would result in bad performance.

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Q37. Which of the following - arrays or LinkedList allow elements to be accessed using index and how ?

Data Structure

^{2018-04-29 09:03:26}

Ans. Arrays allows elements to be accessed directly using the index.

As Array elements are stored in continuous memory locations it's very easy to find the memory address of any element using the formula as following

Memory Address of Array start or index 0 + ( Size of array element * Index )

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Q38. Difference between Arrays and LinkedList ?

Data Structure

^{2018-04-26 18:57:20}

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Q39. How are hash codes generated ?

Data Structure

^{2018-04-18 19:12:52}

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Q40. Create a stack of specific size using arrayList?

Data Structure

^{2018-04-04 21:33:45}

Ans. public class StackUsingArrayList {
   public static void main(String[] args) {
      List list = new ArrayList();
      list.add("A");
      list.add("B");
      list.add("C");

      Stack stack = new Stack();

      list.forEach(a -> stack.add(a));
      System.out.println(stack);

   }
}

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