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

Graph representation, adjacency multi list

adjacency multi list

The best average behaviour, The best average behaviour is shown by  Qui...

The best average behaviour is shown by  Quick Sort

Explain insertion sort, Q. Explain the insertion sort with a proper algorit...

Q. Explain the insertion sort with a proper algorithm. What is the complication of insertion sort in the worst case?

Database design and sql queries, In assignment, you have already started th...

In assignment, you have already started the process of designing a database for the Beauty Salon mini-case (enclosed again below), mainly in the phase of conceptual database design

Full binary trees, Full Binary Trees: A binary tree of height h that had 2...

Full Binary Trees: A binary tree of height h that had 2h -1 elements is called a Full Binary Tree. Complete Binary Trees: A binary tree whereby if the height is d, and all of

A full binary tree with 2n+1 nodes, A full binary tree with 2n+1 nodes have...

A full binary tree with 2n+1 nodes have n non-leaf nodes

Determine the types of java, Determine the types of JAVA Java has two p...

Determine the types of JAVA Java has two parts... 1. Core language -- variables, arrays, objects o Java Virtual Machine (JVM) runs the core language o Core language is

Algorithm to merge two sorted arrays with third array, Q. Write down an alg...

Q. Write down an algorithm to merge the two sorted arrays into the third array. Do  not perform the sort function in the third array.                           Ans: void m

Stack, write pseudocode to implement a queue with two stacks

write pseudocode to implement a queue with two stacks

Project, human resource management project work in c++

human resource management project work in c++

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