Q.Fill in the blank
This question tests your understanding of Queue and Deque data structures, including their definitions, operational principles (FIFO), standard terminology, and how elements are inserted and deleted.
Let's break down each blank and understand the underlying concepts.
a) ____________ is a linear list of elements in which insertion and deletion takes place from different ends.
A Queue is a linear data structure that follows a specific order for operations. Elements are added at one end, called the rear (or tail), and removed from the other end, called the front (or head). This characteristic of having different ends for insertion and deletion is fundamental to a queue.
- Answer: Queue
b) Operations on a queue are performed in ____________ order.
The order in which elements are processed in a queue is FIFO, which stands for First-In, First-Out. This means the element that was added first to the queue will be the first one to be removed. Think of a line at a ticket counter: the person who arrived first is the first to be served.
- Answer: FIFO (First-In, First-Out)
c) Insertion operation in a queue is called ____________ and deletion operation in a queue is called ____________.
The standard terminology for operations on a queue is specific:
-
Adding an element to the rear of a queue is called Enqueue.
-
Removing an element from the front of a queue is called Dequeue.
-
Answer: Enqueue, Dequeue
d) Deletion of elements is performed from ____________ end of the queue.
As established by the FIFO principle and the definition of a queue, elements are always removed from the front end. The element at the front is the one that has been in the queue the longest.
- Answer: Front
e) Elements 'A','S','D' and 'F' are present in the queue, and they are deleted one at a time, ____________ is the sequence of element received.
Given the elements 'A', 'S', 'D', 'F' are in the queue, and knowing that a queue operates on a FIFO principle, the element that entered first will be deleted first. Assuming 'A' was inserted first, followed by 'S', then 'D', and finally 'F', the deletion sequence will mirror the insertion sequence.
Let's trace the deletions:
| Step | Queue State (Front to Rear) | Element Deleted | Sequence Received |
|---|---|---|---|
| 1 | ['A', 'S', 'D', 'F'] | 'A' | 'A' |
| 2 | ['S', 'D', 'F'] | 'S' | 'A', 'S' |
| 3 | ['D', 'F'] | 'D' | 'A', 'S', 'D' |
| 4 | ['F'] | 'F' | 'A', 'S', 'D', 'F' |
- Answer: A, S, D, F
f) ____________ is a data structure where elements can be added or removed at either end, but not in the middle.
This describes a Deque, which is short for Double-ended queue. Unlike a regular queue, a deque allows insertions and deletions from both the front and the rear ends. However, operations are still restricted to the ends; you cannot add or remove elements from arbitrary positions in the middle.
- Answer: Deque (Double-ended queue)
g) A deque contains 'z','x','c','v' and 'b'. Elements received after deletion are 'z','b','v','x' and 'c'. ____________ is the sequence of deletion operation performed on deque.
We need to determine the sequence of deletion operations (delete from front or delete from rear) that would result in the given output sequence, starting from the initial deque state.
Initial Deque: ['z', 'x', 'c', 'v', 'b'] (where 'z' is the front and 'b' is the rear).
Received sequence: ['z', 'b', 'v', 'x', 'c']
Let's trace the operations:
| Step | Current Deque (Front to Rear) | Element Received | Operation Performed |
|---|---|---|---|
| 1 | ['z', 'x', 'c', 'v', 'b'] | 'z' | 'z' is at the front. So, delete_front() |
| 2 | ['x', 'c', 'v', 'b'] | 'b' | 'b' is at the rear. So, delete_rear() |
| 3 | ['x', 'c', 'v'] | 'v' | 'v' is at the rear. So, delete_rear() |
| 4 | ['x', 'c'] | 'x' | 'x' is at the front. So, delete_front() |
| 5 | ['c'] | 'c' | 'c' is at the front (or rear). So, delete_front() |
- Answer: delete_front(), delete_rear(), delete_rear(), delete_front(), delete_front()
a) Queue is a linear list of elements in which insertion and deletion takes place from different ends.
b) Operations on a queue are performed in FIFO (First-In, First-Out) order.
c) Insertion operation in a queue is called Enqueue and deletion operation in a queue is called Dequeue.
d) Deletion of elements is performed from Front end of the queue.
e) Elements 'A','S','D' and 'F' are present in the queue, and they are deleted one at a time, A, S, D, F is the sequence of element received.
f) Deque (Double-ended queue) is a data structure where elements can be added or removed at either end, but not in the middle.
g) A deque contains 'z','x','c','v' and 'b'. Elements received after deletion are 'z','b','v','x' and 'c'. delete_front(), delete_rear(), delete_rear(), delete_front(), delete_front() is the sequence of deletion operation performed on deque.
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