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

Evaluation of arithmetic expressions, Stacks are often used in evaluation o...

Stacks are often used in evaluation of arithmetic expressions. An arithmetic expression contains operands & operators. Polish notations are evaluated through stacks. Conversions of

Circular doubly link list, what is circular doubly link list?write down the...

what is circular doubly link list?write down the algorithm for insertion of elements in circular doubly link list

Internal sorting, In internal sorting, all of the data to be sorted is obta...

In internal sorting, all of the data to be sorted is obtainable in the high speed main memory of the computer. We will learn the methods of internal sorting which are following:

Search engines - applications of linear and binary search, Search engines e...

Search engines employ software robots to survey the Web & build their databases. Web documents retrieved & indexed through keywords. While you enter a query at search engine websit

Efficiency of linear search, Efficiency of Linear Search How much numbe...

Efficiency of Linear Search How much number of comparisons is there in this search in searching for a particular element? The number of comparisons based upon where the reco

Recurrence relation, solve the following relation by recursive method: T(n...

solve the following relation by recursive method: T(n)=2T(n^1/2)+log n

Compute the shortest paths to all network nodes, (i)  Consider a system usi...

(i)  Consider a system using flooding with hop counter. Suppose that the hop counter is originally set to the "diameter" (number of hops in the longest path without traversing any

Explain the method of overlapping and intersecting, Overlapping or Interse...

Overlapping or Intersecting A polygon overlaps or intersects the current background if any of its sides cuts the edges of the viewport as depicted at the top right corner of th

Progrrame, how to write a code for for a company , for calculate the salary...

how to write a code for for a company , for calculate the salary pay

What is algorithm, What is Algorithm A finite sequence of steps for a...

What is Algorithm A finite sequence of steps for accomplishing some computational task. An algorithm should Have steps which are simple and definite enough to be done

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