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

How many nodes in a tree have no ancestor, How many nodes in a tree have no...

How many nodes in a tree have no ancestors 1 node in atree have no ancestors.

Define tree ?, A tree is a non-empty set one component of which is designat...

A tree is a non-empty set one component of which is designated the root of the tree while the remaining components are partitioned into non-empty groups each of which is a subtree

Explain principle of optimality, Explain principle of Optimality It ind...

Explain principle of Optimality It indicates that an optimal solution to any instance of an optimization problem is composed of  optimal solutions to its subinstances.

Mathematical-model with a collection of operations, A mathematical-model wi...

A mathematical-model with a collection of operations described on that model is known as??? Abstract Data Type

Quick sort, 24 56 47 35 10 90 82 31

24 56 47 35 10 90 82 31

Explain best - fit method, Best - Fit Method: - This method obtains the sma...

Best - Fit Method: - This method obtains the smallest free block whose  size is greater than or equal to get such a block by traversing the whole free list follows.

Explain the term group support system, (a) Explain the term Group Support S...

(a) Explain the term Group Support System and elaborate on how it can improve groupwork. (b) Briefly explain three advantages of simulation. (c) Explain with the help of a

Computer applicatios, What are the features of an expert system

What are the features of an expert system

Preorder - postorder and inorder, 1) preorder, postorder and inorder 2) ...

1) preorder, postorder and inorder 2) The main feature of a Binary Search Tree is that all of the elements whose values is less than the root reside into the nodes of left subtr

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

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