1

Sorting AnimationChapter 10

2

Selection Sort

Another way of sorting is the selection sort

The main idea is to keep finding the smallest (and next smallest) items in the array

And move them into correct position (swap)

3

Selection Sort

45 < smallest? F

45

smallest

0

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

0

n

4

Selection Sort

32 < smallest? T

45

smallest

0

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

1

n

5

Selection Sort

32 < smallest? T

32

smallest

1

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

1

n

6

Selection Sort

56 < smallest? F

32

smallest

1

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

2

n

7

Selection Sort

9 < smallest? T

32

smallest

1

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

3

n

8

Selection Sort

9 < smallest? T

9

smallest

3

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

3

n

9

Selection Sort

21 < smallest? F

9

smallest

3

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

4

n

10

Selection Sort

77 < smallest? F

9

smallest

3

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

5

n

11

Selection Sort

17 < smallest? F

9

smallest

3

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

6

n

12

Selection Sort—SWAP!

9

smallest

3

small_pos

0

k

data

0 1 2 3 4 5 6 7

45 32 56 9 21 77 18 17

6

n

Swap(data[k], data[small_pos]);

13

Selection Sort

32 < smallest? F

32

smallest

1

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

1

n

14

Selection Sort

32 < smallest? F

32

smallest

1

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

2

n

15

Selection Sort

45 < smallest? F

32

smallest

1

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

3

n

16

Selection Sort

21 < smallest? T

32

smallest

1

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

4

n

17

Selection Sort

21 < smallest? T

21

smallest

4

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

4

n

18

Selection Sort

77 < smallest? F

21

smallest

4

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

5

n

19

Selection Sort

18 < smallest? T

21

smallest

4

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

6

n

20

Selection Sort

18 < smallest? T

18

smallest

6

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

6

n

21

Selection Sort

17 < smallest? T

18

smallest

6

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

7

n

22

Selection Sort

17 < smallest? T

17

smallest

7

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

7

n

23

Selection Sort—SWAP!

17

smallest

7

small_pos

1

k

data

0 1 2 3 4 5 6 7

9 32 56 45 21 77 18 17

7

n

Swap(data[k], data[small_pos]);

24

Selection Sort—and so on

56 < smallest? F

56

smallest

2

small_pos

2

k

data

0 1 2 3 4 5 6 7

9 17 56 45 21 77 18 32

2

n