User Account

All Pages

What is Polyphase Sort, Data Structure & Algorithms

Assignment Help:
One of the best known methods for external sorting on tapes is the polyphase sort.

Principle: The basic strategy of this sort is to distribute ordered initial runs of predetermined size on the available tapes and then to repeatedly merge these runs in multiple phases in which each phase has a predetermined number of merges before a new target tape is selected.

To distribute the initial runs a Fibonacci distribution is adopted. After the distribution of the runs according to Fibonacci distribution, the merging procedure is continued until the tape with the least number of run lists is empty. When this occurs the remaining working tapes are logically rotated such that the newly emptied tape becomes the new target tape and the old target tape then becomes one of the working tapes to be merged. The sort ends when all runs are merged into one.

Let the number of tapes be T and p = T - 1. The Fibonacci distribution for p = 3 is given.

Level

s
Tape
Total number of runs
1
2
3
1
0
0
1
1
2
1
1
1
3
3
1
2
2
5
4
2
3
4
9
5
4
6
7
17
6
7
11
13
31
7
13
20
24
57
8
24
37
44
105
9
44
68
81
193
Algorithm:

1. Let A be the list of N unsorted elements and R be the number of runs.

2. Let T1, T2, T3 and T4 be the tapes on which sorting is done.

3. Split the list A into R=N runs so that each run has only one element.

4. If R is not equal to perfect Fibonacci distribution then add dummy records to bring up perfect Fibonacci distribution.

5. Distribute the records in the remaining tapes according to the Fibonacci distribution.

6. Merge 3 runs, one from each tape and put into next empty tape.

7. Repeat step 6 till a single run is generated.

Related Discussions:- What is Polyphase Sort

Define binary search technique, Binary search technique:-  This techniq...

Binary search technique:-  This technique is applied to an ordered list where elements are arranged either in ascending order or descending order. The array is separated into t

Context sensitive f1 help on a field, In what ways we can get the context s...

In what ways we can get the context sensitive F1 help on a field?' Data element documentation. Data element additional text in screen painter. Using the process on help r

Stack, write pseudocode to implement a queue with two stacks

write pseudocode to implement a queue with two stacks

Binary search tree, Objectives The purpose of this project is to give yo...

Objectives The purpose of this project is to give you significant exposure to Binary Search Trees (BST), tree traversals, and recursive code. Background An arbitrary BST i

File organization, Define File organization''s and it''s types

Define File organization''s and it''s types

Algorithm, write an algorithm for the gpa of six students

write an algorithm for the gpa of six students

Stack, Explain the array and linked list implementation of stack

Explain the array and linked list implementation of stack

Determine the term - loops, Loops There are 3 common ways of performin...

Loops There are 3 common ways of performing a looping function: for ... to ... next, while ... endwhile and repeat ... until The below example input 100 numbers and find

Functions and modelling the data flows, Read the scenario (Pickerings Prope...

Read the scenario (Pickerings Properties). (a) List the functions of the system, as perceived by an external user. (b) List the external entities. Note that because we are mo

Multiple Queues in a single dimension array, Implement multiple queues in a...

Implement multiple queues in a single dimensional array. Write algorithms for various queue operations for them.

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd