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

Construct a minimum spanning tree, Construct G for α, n, and W given as com...

Construct G for α, n, and W given as command line parameters. Throw away edges that have an asymmetric relation between nodes. That is, if A is connected to B, but B is not connect

Name the five popular hashing functions, Five popular hashing functions are...

Five popular hashing functions are as follows: 1) Division Method 2) Midsquare Method 3) Folding Method 4) Multiplicative method 5) Digit Analysis

Circular linklist, write an algorithm to insert an element at the beginning...

write an algorithm to insert an element at the beginning of a circular linked list?

Create accessors for this data structure, Create a Money data structure tha...

Create a Money data structure that is made up of amount and currency. (a) Write a constructor for this data structure (b) Create accessors for this data structure (c) Writ

Tic Tac Toe game , Book to refer: Introduction to Algorithms, 3rd Ed, by Cl...

Book to refer: Introduction to Algorithms, 3rd Ed, by Clifford Stein, Thomas H. Cormen, Ronald Rivest, Charles E. Leiserson Question: Tic Tac Toe game -Design a GUI and implement

Merging 4 sorted files containing 50, Merging 4 sorted files having 50, 10,...

Merging 4 sorted files having 50, 10, 25 and 15 records will take time  O (100)

Develop a material requirements plan, The below figure illustrates the BOM ...

The below figure illustrates the BOM (Bill of Materials) for product A. The MPS (Material requirements Planning) start row in the master production schedule for product A calls for

Signals, How does cpu''s part tming and controls generate and controls sign...

How does cpu''s part tming and controls generate and controls signls in computer?

Threads in main method, Create main method or a test class that creates 2 E...

Create main method or a test class that creates 2 Element objects that are neighbours of each other, the first element temperature set at 100, the 2nd at 0 and use an appropriate h

Program insertion of a node into any circular linked list, Program Insertio...

Program Insertion of a node into any Circular Linked List Figure depicts a Circular linked list from which an element was deleted. ALGORITHM (Deletion of an element from a

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