SELECTION SORT

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Submitted by:

1 Arifarina

2 sakil

3 sabuj sarkar

4 Himu

Submitted to:

Mr.Tahzibul Islam

Lecturer,Department of

cse.Dhaka International University.

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DATA STRUCTURES-CSE 205PRESENTATION

ROAD MAP

1 Definition

2 Example

3 Algorithm

4 Ascending And Dscending order.

6 Mathematical definition

7Question And Answer

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▪The selection sort is a combination of searching and sorting.

▪In selection sort, sorting is done after selecting a particular smallest or largest element from an array and shifted it to a particular location in an array.

▪During each pass, the unsorted element with the smallest (or largest) value is moved to its proper position in the array.

 

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▪Let's look at our same table of elements Using a selection sort for ascending order

▪The number of times the sort passes throughthe array is one less than the number of itemsin the array.

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Selection Sort Example

Sorted Unsorted

23 78 45 8 32 56 Original List

8 78 45 23 32 56 After pass 1

8 23 45 78 32 56 After pass 1

8 23 32 78 45 56 After pass 1

8 23 32 45 78 56 After pass 1

8 23 32 45 56 78 After pass 1

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Ascending order Algorithm: Selection sort(L,N)

1 Repeat steps 2 to 6 for I=1 to N 2 set min:=I 3 Repeat steps 4 & 5 for J=I+1 to N 4 if list [J]<list [min] then 5 set lin:=J 6 swap (list [I],list [min]) 7 End.

L=List of items.

N=Totel number of items in the list .

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  ▪ In the selection sort, the inner loop finds the next smallest value and the outer loop places that value into its proper location.

Array

40 50 60 10 30 20

1-pass

10 50 60 40 30 20

2-pass

10 20 60 40 30 50

3-pass

10 20 30 40 60 50

4-pass

10 20 30 40 60 50

5-pass

10 20 30 40 50 60

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Dscending order Algorithm:selection sort(L,N)

1 Repeat steps 2 to 6 for I=1 to N2 min:=I3 Repeat steps 4 & 5 for J=I+1 to N4 if list [J]>list [mix] then5 set mix:=J6 swap(list [I],list-[min])7 End

L=list of items

N=Totel number of items in the list .

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Array

70 50 11 10 40 20

1-pass

70 50 11 10 40 20

2-pass

70 50 11 10 40 20

3-pass

70 50 40 10 11 20

4-pass

70 50 40 20 11 10

5-pass

70 50 40 20 11 10

▪In the selection sort, the inner loop finds the next largest value and the outer loop places that value into its proper location.

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i:0; j:1 (7-1);min=I;if(arr[j]<arr[min]) {min=j;} finally swap (a[i],a[min])

89 45 68 90 29 34 17» 17| 45 68 90 29 34 89

i:1;j:2 (7-1); min=I;if(arr[j]<arr[min]) {min=j;} finally swap (a[i],a[min])

17|45 68 90 29 34 89»17|29 |68 90 45 34 89

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i:2;j:3 (7-1); min=I;if(arr[j]<arr[min]) {min=j;}finally swap (a[i],a[min])

17|29 68 90 45 34 89

17|29|34| 90 45 68 89

Complexity is O(n2).

Kitkat

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* Any query?

* Any question or any point which you doesn’t get?

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THANK YOU!