UNDERSTANDING THE NEED FOR SORTING DATA

rach wrote:

rachellgrace wrote:

Can you suggest guys another way of sorting data?

invented by Donald Shell
Algorithm

   start separation = number of elements / 2
   compare a[i] and a[i+separation]
   swap if necessary
   do for each element of array i = 0 to a.length – separation
   set separation = separation /2
   recompare all the elements

separation calculation

   shell suggested /2
   other sequences give great improvement
   note figure 7.3 does not / 2 properly

Code Methods: shellsort
Average Case Shellsort : Open Problem

Mergesort

Code Methods: mergesort (2), merge
Worst Case: O(NlogN)
Recursively merges two sorted lists
Time to merge two sorted lists is linear (N-1 comparisons)
1 13 24 26 merge 2 15 27 38 gives 1 2 13 15 24 26 27 38
Classic Divide and Conquer Strategy
If more than one element, divide and merge sort the first and second
half
Analysis
Recurrance Relation
T(1) = 1
T(N) = 2T(N/2) + N
T(N)/ N = T(N/2)/N/2 + 1
T(N/2) / N/2 = T(N/4) / N/4 + 1
T(2) / 2 = T(1)/1 + 1
Sum up all of the equations
T(N)/N = T(1)/1 + logN <- this logN is the sum of the 1’s
T(N) = NlogN + N = O(NlogN)
Uses extra memory to merge and copy back into array
Merging is cornerstone of external sorting routines
Not often used for main memory sorts
Can also do it not recursively
Or can use less memory – much more complex algorithm (impractical)

ahnmaria wrote:

What is the meaning of ASCII?

ASCII Code. ASCII, stands for American Standard Code for Information Interchange. It's a 7-bit character code where every single bit represents a unique character.

jennyy wrote:

rach wrote:

rachellgrace wrote:

Can you suggest guys another way of sorting data?

invented by Donald Shell
Algorithm

   start separation = number of elements / 2
   compare a[i] and a[i+separation]
   swap if necessary
   do for each element of array i = 0 to a.length – separation
   set separation = separation /2
   recompare all the elements

separation calculation

   shell suggested /2
   other sequences give great improvement
   note figure 7.3 does not / 2 properly

Code Methods: shellsort
Average Case Shellsort : Open Problem

Mergesort

   Code Methods: mergesort (2), merge
   Worst Case: O(NlogN)
   Recursively merges two sorted lists
   Time to merge two sorted lists is linear (N-1 comparisons)
   1 13 24 26 merge 2 15 27 38 gives 1 2 13 15 24 26 27 38
   Classic Divide and Conquer Strategy
   If more than one element, divide and merge sort the first and second
   half
   Analysis
       Recurrance Relation
       T(1) = 1
       T(N) = 2T(N/2) + N
       T(N)/ N = T(N/2)/N/2 + 1
       T(N/2) / N/2 = T(N/4) / N/4 + 1
       T(2) / 2 = T(1)/1 + 1
       Sum up all of the equations
       T(N)/N = T(1)/1 + logN <- this logN is the sum of the 1’s
       T(N) = NlogN + N = O(NlogN)
   Uses extra memory to merge and copy back into array
   Merging is cornerstone of external sorting routines
   Not often used for main memory sorts
   Can also do it not recursively
   Or can use less memory – much more complex algorithm (impractical)

that is a big help thanks! hope you post some more.

VOVOFRIEND wrote:

ahnmaria wrote:

What is the difference between sequential and chronological order?

Sequential ; Something that is sequential follows a fixed order and thus forms a pattern. ex. The pages are numbered sequentially.
Chronological ; If things are described or shown in chronological order, they are described or shown in the order in which they happened. It relates to the timings of the happenings.

chronological is something that is arrange properly and sequential is like event you set step by step

chelsey wrote:

Data Structure - Sorting Techniques. Sorting refers to arranging data in a particular format. Sorting algorithm specifies the way to arrange data in a particular order.

thank you for this information.

jennyy wrote:

rach wrote:

rachellgrace wrote:

Can you suggest guys another way of sorting data?

invented by Donald Shell
Algorithm

   start separation = number of elements / 2
   compare a[i] and a[i+separation]
   swap if necessary
   do for each element of array i = 0 to a.length – separation
   set separation = separation /2
   recompare all the elements

separation calculation

   shell suggested /2
   other sequences give great improvement
   note figure 7.3 does not / 2 properly

Code Methods: shellsort
Average Case Shellsort : Open Problem

Mergesort

   Code Methods: mergesort (2), merge
   Worst Case: O(NlogN)
   Recursively merges two sorted lists
   Time to merge two sorted lists is linear (N-1 comparisons)
   1 13 24 26 merge 2 15 27 38 gives 1 2 13 15 24 26 27 38
   Classic Divide and Conquer Strategy
   If more than one element, divide and merge sort the first and second
   half
   Analysis
       Recurrance Relation
       T(1) = 1
       T(N) = 2T(N/2) + N
       T(N)/ N = T(N/2)/N/2 + 1
       T(N/2) / N/2 = T(N/4) / N/4 + 1
       T(2) / 2 = T(1)/1 + 1
       Sum up all of the equations
       T(N)/N = T(1)/1 + logN <- this logN is the sum of the 1’s
       T(N) = NlogN + N = O(NlogN)
   Uses extra memory to merge and copy back into array
   Merging is cornerstone of external sorting routines
   Not often used for main memory sorts
   Can also do it not recursively
   Or can use less memory – much more complex algorithm (impractical)

can you give this a reference rachell?

ahnmaria wrote:

What is the difference between sequential and chronological order?

there are no difference between the two haha

ahnmaria wrote:

What is the meaning of ASCII?

ASCII stands for American Standard Code for Information Interchange. Computers can only understand numbers, so an ASCII code is the numerical representation of a character such as 'a' or '@' or an action of some sort. ASCII was developed a long time ago and now the non-printing characters are rarely used for their original purpose. Below is the ASCII character table and this includes descriptions of the first 32 non-printing characters.

ralfh wrote:

ahnmaria wrote:

What is the difference between sequential and chronological order?

actually there is no difference because it is same that sort data but maybe sequence is about having a descending or ascending of any type of character and chronological is about numbers only.

I agree on you. but maybe it depends on the one who will give condition on sequence

This blog is beneficial to those who start on making a program