7/29/2019 1.2 Bubble Sort student.docx

1/2

Bubble Sort

What is bubble sort?

Bubble sort is an algorithm for sorting numbers into ascending order. You

could be asked to trace the algorithm and/or compare how efficient it is.

Bubble Sort Algorithm

Line 10: If there is only one item in the list, stop

Line 20: Make one pass down the list, swapping items as necessary

Line 30: If no swaps occurred then stop, otherwise ignore the last item

and return to step one

In the bubble sort algorithm, the largest number in each pass bubbles to the

top, and then is ignored for each successive pass. Even if all the numbers are

ordered after a pass, the algorithm does not stop until another pass has been

made to ensure there are no swaps to be made.

Example

Use bubble sort to sort the numbers 6, 4, 8, 3, 7, 4 into ascending order

Pass List Notes

Start 6 4 8 3 7 4

Pass 1 4 6 8 3 7 4 Swap 6 and 4

4 6 8 3 7 4 Dont swap 6 and 8

4 6 3 8 7 4 Swap 8 and 3

4 6 3 7 8 4 Swap 8 and 7

4 6 3 7 4 8 Swap 8 and 4

After Pass 1 4 6 3 7 4 8 8 is fixed

Pass 2 4 6 3 7 4 8 Dont swap 4 and 6

4 3 6 7 4 8 Swap 3 and 6

4 3 6 7 4 8 Dont swap 6 and 7

4 3 6 4 7 8 Swap 7 and 4

After Pass 2 4 3 6 4 7 8 7 and 8 are fixed

Pass 3 3 4 6 4 7 8 Swap 4 and 3

3 4 6 4 7 8 Dont swap 4 and 6

3 4 4 6 7 8 Swap 6 and 4

After Pass 3 3 4 4 6 7 8 6, 7 and 8 are fixed

Pass 4 3 4 4 6 7 8 Dont swap 3 and 4

3 4 4 6 7 8 Dont swap 4 and 4

After Pass 4 3 4 4 6 7 8 All are fixed

Bubble Sort

What is bubble sort?

Bubble sort is an algorithm for sorting numbers into ascending order. You

could be asked to trace the algorithm and/or compare how efficient it is.

Bubble Sort Algorithm

Line 10: If there is only one item in the list, stop

Line 20: Make one pass down the list, swapping items as necessary

Line 30: If no swaps occurred then stop, otherwise ignore the last item

and return to step one

In the bubble sort algorithm, the largest number in each pass bubbles to the

top, and then is ignored for each successive pass. Even if all the numbers are

ordered after a pass, the algorithm does not stop until another pass has been

made to ensure there are no swaps to be made.

Example

Use bubble sort to sort the numbers 6, 4, 8, 3, 7, 4 into ascending order

Pass List Notes

Start 6 4 8 3 7 4

Pass 1 4 6 8 3 7 4 Swap 6 and 4

4 6 8 3 7 4 Dont swap 6 and 8

4 6 3 8 7 4 Swap 8 and 3

4 6 3 7 8 4 Swap 8 and 7

4 6 3 7 4 8 Swap 8 and 4

After Pass 1 4 6 3 7 4 8 8 is fixed

Pass 2 4 6 3 7 4 8 Dont swap 4 and 6

4 3 6 7 4 8 Swap 3 and 6

4 3 6 7 4 8 Dont swap 6 and 7

4 3 6 4 7 8 Swap 7 and 4

After Pass 2 4 3 6 4 7 8 7 and 8 are fixed

Pass 3 3 4 6 4 7 8 Swap 4 and 3

3 4 6 4 7 8 Dont swap 4 and 6

3 4 4 6 7 8 Swap 6 and 4

After Pass 3 3 4 4 6 7 8 6, 7 and 8 are fixed

Pass 4 3 4 4 6 7 8 Dont swap 3 and 4

3 4 4 6 7 8 Dont swap 4 and 4

After Pass 4 3 4 4 6 7 8 All are fixed

7/29/2019 1.2 Bubble Sort student.docx

2/2