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

Structure of an avl tree, Given is the structure of an AVL tree: struct ...

Given is the structure of an AVL tree: struct avl { struct node *left; int info; int bf; struct node *right; }; 2) A multiway tree of n order is an ord

The data structure required to evaluate a postfix expression, The data stru...

The data structure needed to evaluate a postfix expression is  Stack

Comparisons between linear and binary search, Comparative Study of Linear a...

Comparative Study of Linear and Binary Search Binary search is lots quicker than linear search. Some comparisons are following: NUMBER OF ARRAY ELEMENTS EXAMINED array

Write the algorithm to find input and output value, This algorithm inputs 5...

This algorithm inputs 5 values and outputs how many input numbers were positive and how many were negative. Data to be used: N = 1, -5, 2, -8, -7

Sparse matrix, How sparse matrix stored in the memory of a computer?

How sparse matrix stored in the memory of a computer?

Explain the question, Merging 4 sorted files having 50, 10, 25 and 15 recor...

Merging 4 sorted files having 50, 10, 25 and 15 records will take time

Array implementation of a queue, Since the stack is list of elements, the q...

Since the stack is list of elements, the queue is also a list of elements. The stack & the queue differ just in the position where the elements may be added or deleted. Similar to

Algorithm.., write an algorithm to sort given numbers in ascending order us...

write an algorithm to sort given numbers in ascending order using bubble sort

Graph and BFS, traverse the graph as BFS

traverse the graph as BFS

Prime''z algorithem, Ask question #explain it beriflyMinimum 100 words acce...

Ask question #explain it beriflyMinimum 100 words accepted#

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