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

Stack flowchart, example of stack using flowchart

example of stack using flowchart

Circularly linked lists implementation, CIRCULARLY LINKED LISTS IMPLEMENTAT...

CIRCULARLY LINKED LISTS IMPLEMENTATION A linked list wherein the last element points to the first element is called as CIRCULAR linked list. The chains do not specified first o

Algorithm that inputs the codes for all items in stock, A shop sells books,...

A shop sells books, magazines and maps. Every item is identified by a unique 4 - digit code. All books have a code which starts with 1, all maps have a code starting with 2 and all

Define an array, Define an array. Array is made up of same data structu...

Define an array. Array is made up of same data structure that exists in any language. Array is set of same data types. Array is the collection of same elements. These same elem

Conversion of general trees to binary trees, Taking a suitable example expl...

Taking a suitable example explains how a general tree can be shown as a Binary Tree. Conversion of general trees to binary trees: A general tree can be changed into an equiv

Program segment for quick sort, Illustrates the program segment for Quick s...

Illustrates the program segment for Quick sort. It uses recursion. Program 1: Quick Sort Quicksort(A,m,n) int A[ ],m,n { int i, j, k; if m { i=m; j=n+1; k

Algorithams example, any simple algoritham questions with answers

any simple algoritham questions with answers

Rotations in binary tree, H o w can you r ot a t e a B i n a r y...

H o w can you r ot a t e a B i n a r y Tr e e? E x pl a i n r i g h t a n d l eft r ot a tion s by taking an e x a mpl e.   If after

What is Polyphase Sort, One of the best known methods for external sorting ...

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 predetermi

Importance of game theory to decisions, Question: (a) Discuss the impor...

Question: (a) Discuss the importance of game theory to decisions. (b) Explain the following: (i) saddle point, (ii) two-person zero-sum game. (c) Two leading ?rms, ABC Ltd 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