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

Application of stack, to find binary value of an integer

to find binary value of an integer

Selection sort, how to reduce the number of passes in selection sort

how to reduce the number of passes in selection sort

Tree traversals, There are three kinds of tree traversals, namely, Postorde...

There are three kinds of tree traversals, namely, Postorder , Preorder and Inorder. Preorder traversal: Each of nodes is visited before its children are visited; first the roo

State the ways to construct container taxonomy, State the ways to construct...

State the ways to construct container taxonomy There are several ways that we could construct our container taxonomy from here; one way that works well is to make a fundamental

Merge sort , What is the best-case number of comparisons performed by merge...

What is the best-case number of comparisons performed by mergesort on an input sequence of 2 k distinct numbers?

Explain the prim''s minimum spanning tree algorithm, Question 1. Explai...

Question 1. Explain the different types of traversal on binary tree 2. Explain the Prim's minimum spanning tree algorithm 3. Differentiate fixed and variable storage allo

Simulation of queues, Simulation is the process of making an abstract model...

Simulation is the process of making an abstract model of a real world situation in order to be aware of the effect of modifications and alterations and the effect of introducing nu

Graph traversal schemes, Q. Explain various graph traversal schemes and wri...

Q. Explain various graph traversal schemes and write their advantages and disadvantages. A n s . Graph Traversal Scheme is explained below In many troubles we wish

DAA, what do we use asymptotic notation in study of algorithm?Describe vari...

what do we use asymptotic notation in study of algorithm?Describe various asymptotic notation and give their significance.

Explain the stack, QUESTION Explain the following data structures: ...

QUESTION Explain the following data structures: (a) List (b) Stack (c) Queues Note : your explanation should consist of the definition, operations and examples.

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