Understanding Selection Sort Algorithm

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 data small_pos smallest n 0 45 0 k 45 < smallest? F 0

4. Selection Sort data small_pos smallest n 0 45 1 k 32 < smallest? T 0

5. Selection Sort data small_pos smallest n 1 32 1 k 32 < smallest? T 0

6. Selection Sort data small_pos smallest n 1 32 2 k 56 < smallest? F 0

7. Selection Sort data small_pos smallest n 1 32 3 k 9 < smallest? T 0

8. Selection Sort data small_pos smallest n 3 9 3 k 9 < smallest? T 0

9. Selection Sort data small_pos smallest n 3 9 4 k 21 < smallest? F 0

10. Selection Sort data small_pos smallest n 3 9 5 k 77 < smallest? F 0

11. Selection Sort data small_pos smallest n 3 9 6 k 17 < smallest? F 0

12. Selection Sort—SWAP! data small_pos smallest n 3 9 6 k Swap(data[k], data[small_pos]); 0

13. Selection Sort data small_pos smallest n 1 32 1 k 32 < smallest? F 1

14. Selection Sort data small_pos smallest n 1 32 2 k 32 < smallest? F 1

15. Selection Sort data small_pos smallest n 1 32 3 k 45 < smallest? F 1

16. Selection Sort data small_pos smallest n 1 32 4 k 21 < smallest? T 1

17. Selection Sort data small_pos smallest n 4 21 4 k 21 < smallest? T 1

18. Selection Sort data small_pos smallest n 4 21 5 k 77 < smallest? F 1

19. Selection Sort data small_pos smallest n 4 21 6 k 18 < smallest? T 1

20. Selection Sort data small_pos smallest n 6 18 6 k 18 < smallest? T 1

21. Selection Sort data small_pos smallest n 6 18 7 k 17 < smallest? T 1

22. Selection Sort data small_pos smallest n 7 17 7 k 17 < smallest? T 1

23. Selection Sort—SWAP! data small_pos smallest n 7 17 7 k Swap(data[k], data[small_pos]); 1

24. Selection Sort—and so on data small_pos smallest n 2 56 2 k 56 < smallest? F 2