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

B-tree of minimum degree t can maximum pointers in a node, A B-tree of mini...

A B-tree of minimum degree t can maximum pointers in a node T pointers in a node.

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

..#title, whate is meant by the term heuristic

whate is meant by the term heuristic

Program, insertion and deletion in a tree

insertion and deletion in a tree

Problem logicall, Given a list containing Province, CustomerName and SalesV...

Given a list containing Province, CustomerName and SalesValue (sorted by Province and CustomerName), describe an algorithm you could use that would output each CustomerName and Sal

Variable length codes, Variable length codes (Niveau I) Code the following ...

Variable length codes (Niveau I) Code the following sequence of integers (2, 4, 2, 8, 3, 1, 4, 5, 13, 2) with • unary codes • ? codes • d codes • Rice codes (for a suitable l) and

Quicksort and bubble sort algorithms, Task If quicksort is so quick, w...

Task If quicksort is so quick, why bother with anything else? If bubble sort is so bad, why even mention it? For that matter, why are there so many sorting algorithms? Your

Acyclic graph, Tree is a widely used data structure employed for representi...

Tree is a widely used data structure employed for representing several problems. We studied tree like a special case of acyclic graph. Though, rooted trees are most prominent of al

Depth-First Traversal, With the help of a program and a numerical example e...

With the help of a program and a numerical example explain the Depth First Traversal of a tree.

Procedures, what is far and near procedures in system programming?

what is far and near procedures in system programming?

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