postfix conversions Quiz - ICSE Class 12 Computer Science

Free practice quiz: postfix conversions (ICSE Class 12 Computer Science). 48 multiple-choice questions with answers and explanations. Play online, no sign-up needed.

This ICSE Class 12 Computer Science practice quiz has 48 multiple-choice questions on postfix conversions, and 48 of them come with an explanation. Try the 5 sample questions below (tap an option to check yourself), then play the full quiz online. No sign-up needed.

Sample questions

1. In a singly linked list, if the head pointer is NULL, what does it signify?

   1. The list is full
   2. The list is empty
   3. The list has only one node
   4. The list is corrupted
   Show answer

   Answer: B. The list is empty

   In a singly linked list, the head pointer points to the first node. If the head pointer is NULL, it means there are no nodes in the list, hence the list is empty.

2. Which operation on a stack would result in an 'underflow' error?

   1. Pushing an element onto an empty stack
   2. Popping an element from a non-empty stack
   3. Popping an element from an empty stack
   4. Peeking at an element in a non-empty stack
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   Answer: C. Popping an element from an empty stack

   Stack underflow occurs when an attempt is made to pop or peek at an element from an empty stack. There are no elements to retrieve, hence the error.

3. Which type of binary tree traversal visits nodes in ascending order of their keys?

   1. Pre-order
   2. In-order
   3. Post-order
   4. Level-order
   Show answer

   Answer: B. In-order

   An in-order traversal of a Binary Search Tree (BST) visits the nodes in ascending order of their keys. The process is: traverse left subtree, visit root, traverse right subtree.

4. Which property does a balanced binary search tree aim to maintain?

   1. Minimum height for the number of nodes
   2. Maximum height for the number of nodes
   3. Equal number of nodes in left and right subtrees
   4. Constant height regardless of the number of nodes
   Show answer

   Answer: A. Minimum height for the number of nodes

   A balanced binary search tree (like AVL trees or Red-Black trees) ensures that the height of the tree remains logarithmic with respect to the number of nodes (O(log n)). This is achieved by maintaining a relatively small height, which leads to efficient search, insertion, and deletion operations with an average and worst-case time complexity of O(log n).

5. What is the time complexity for deleting an element from the front of a queue implemented using a singly linked list?

   1. O(1)
   2. O(log n)
   3. O(n)
   4. O(n^2)
   Show answer

   Answer: A. O(1)

   Deleting an element from the front of a queue implemented with a singly linked list is an O(1) operation. This involves simply updating the head pointer to point to the next node in the list.

More questions in this quiz

Answers and explanations are in the full quiz.

1. What is the time complexity of inserting an element at the beginning of a singly linked list?
2. Which data structure operates on the LIFO (Last-In, First-Out) principle?
3. When converting an infix expression to postfix, which operator has the highest precedence?
4. What is the output of the following postfix expression: 5 3 + 2 * 8 / ?
5. In a binary tree, what is the maximum number of nodes at level k (where the root is at level 0)?
6. Which traversal order visits the root node LAST in a Binary Search Tree?
7. A deque (double-ended queue) supports insertion and deletion from which ends?
8. Consider a singly linked list with nodes containing data and a 'next' pointer. If you want to delete the last node, what is the minimum time complexity required?
9. Convert the following infix expression to postfix: (A + B) * C - D / E
10. What is the worst-case time complexity for searching an element in a binary search tree that is skewed like a linked list?
11. Which of the following is NOT a valid operation for a standard stack?
12. In a singly linked list, if you need to insert a node at the end, what is the most efficient approach if you don't have a tail pointer?
13. What is the primary characteristic of a queue data structure?
14. Which of the following is the postfix form of the infix expression 'A * (B + C) / D'?
15. Consider a binary tree where every node has zero or two children. What is this type of tree called?
16. If a stack contains elements [10, 20, 30] where 30 is at the top. What is the state of the stack after performing a POP operation followed by a PUSH of 40?
17. What is the time complexity of inserting an element at the end of a singly linked list if a tail pointer is maintained?
18. If you push elements 1, 2, 3, 4, 5 onto a stack and then pop them, in what order will they be popped?
19. Which operation is typically O(1) for a queue implemented using a doubly linked list?
20. What is the postfix equivalent of the infix expression 'A - B + C * D / E'?
21. In a binary tree, if a node has only one child, which child can it have to maintain the Binary Search Tree property?
22. Which data structure would be most appropriate for implementing a browser's 'undo' functionality?
23. Consider a singly linked list. If you want to insert a node in the middle (say, after the k-th node), what is the minimum time complexity?
24. What happens when you perform an enqueue operation on a queue that has reached its maximum capacity (if it's a fixed-size queue)?
25. Convert the following infix expression to postfix: A / B * C + D
26. If a queue has elements [X, Y, Z] where X is at the front, what is the state of the queue after a DEQUEUE operation followed by an ENQUEUE of W?
27. Which of the following data structures can be used to implement both a stack and a queue efficiently?
28. What is the primary disadvantage of using a simple array for implementing a queue, especially for large numbers of elements?
29. In a post-order traversal of a binary tree, when is the root node visited?
30. Which of the following expressions is NOT a valid postfix expression?
31. If you are given a doubly linked list and need to insert a node BEFORE a given node (pointer to that node is provided), what is the time complexity?
32. When converting the infix expression `a+b*(c^d-e)^(f+g*h)-i` to postfix, what is the correct order of operations for the `*`, `^`, and `-` operators from left to right in the postfix string?
33. Consider an empty binary tree. If you insert the value 5, then 3, then 7, then 2, then 4, then 6, then 8. What is the resulting tree structure?
34. Which method is commonly used to implement a Deque using arrays to handle wrap-around efficiently?
35. Consider a Binary Search Tree. If a node is deleted, and it has two children, what is the standard replacement for the node?
36. Which of the following is a disadvantage of using a linked list over an array for implementing a stack?
37. What is the time complexity to access the k-th element in a singly linked list?
38. In a circular queue implemented with a circular array, if the front and rear pointers are equal, what does it signify?
39. Convert the infix expression `A + B / C * D - E` to postfix, assuming standard operator precedence and left-to-right associativity for operators of equal precedence.
40. In a binary tree, what is the maximum depth of a node?
41. Which of the following is the primary advantage of using a linked list over an array for dynamic data structures where frequent insertions/deletions occur?
42. Which operation on a queue has a time complexity of O(1) if implemented using a linked list with pointers to both head and tail?
43. What is the primary purpose of a dequeue (double-ended queue)?

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