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

Binary search technique, Q. Describe the basic concept of binary search tec...

Q. Describe the basic concept of binary search technique? Is it more efficient than the sequential search?         Ans : The bin ary search technique:- This tec

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.

Quick sort method, Q. Explain quick sort? Sort the given array using quick ...

Q. Explain quick sort? Sort the given array using quick sort method. 24 56 47 35 10 90 82 31

Abstract data type-list, It is a useful tool for indicating the logical pro...

It is a useful tool for indicating the logical properties of data type. It is a collection of values & a set of operations on those values. Methodically, "a TYPE is a set, & elemen

Bubble sort, #question bubble sort..

#question bubble sort..

Write algorithm for post-order traversal, P os t - o r d e r T ...

P os t - o r d e r T r av er sal :  This can be done by both iteratively and recursively. The iterative solution would require a modification or alteration of the in-

Determine the space complexity of euclid algorithm, 1)      Why space compl...

1)      Why space complexity is comparatively more critical than time complexity? 2)      Determine the space complexity of Euclid Algorithm?

Importance of object-oriented over java, Importance of Object-Oriented over...

Importance of Object-Oriented over java Java is basically based on OOP notions of classes and objects. Java uses a formal OOP type system that should be obeyed at compile-t

What are the specific needs for realism, Normal 0 false false...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Data searching, In file access: what is the difference between serial, seq...

In file access: what is the difference between serial, sequential and indexed sequential searching

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