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

Homework, Write a recursive function the computes the number of digits in a...

Write a recursive function the computes the number of digits in a positive integer n. For example if n = 6598, the function should return 4. Find a variant expression and a thresho

Merge sorting, ESO207: Programming Assignment 1 Due on 6 Sept, 2015. To be ...

ESO207: Programming Assignment 1 Due on 6 Sept, 2015. To be submitted online. Problem In this assignment you are required to implement k-way Merge Sort algorithm. In this version p

Characteristics of good algorithms, What do we mean by algorithm? What are ...

What do we mean by algorithm? What are the characteristics of a good and relevant algorithm? An algorithm is "a step-by-step procedure for finishing some task'' An algorithm c

Function performs multiplication of two numbers, You need to write a functi...

You need to write a function that performs multiplication of two numbers in your data structure. Again, remember how you multiply numbers in base 10 and you should be fine. Multipl

Merge sort , What is the best-case number of comparisons performed by merge...

What is the best-case number of comparisons performed by mergesort on an input sequence of 2 k distinct numbers?

Deletion from a red-black tree, Deletion in a RBT uses two main processes, ...

Deletion in a RBT uses two main processes, namely, Procedure 1: This is utilized to delete an element in a given Red-Black Tree. It involves the method of deletion utilized in

Sorting, explain quick sort algorithm

explain quick sort algorithm

Tower of hanoi, how do we use 4-discs stack to solve tower of hanoi problem...

how do we use 4-discs stack to solve tower of hanoi problem and write an algorithm to solve it?

Recursion, differences between direct and indirect recursion

differences between direct and indirect recursion

Convertion, how we can convert a graph into tree

how we can convert a graph into tree

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