Merge Sorts

Which of these algorithms sorts items by first splitting the list of items down into smaller and smaller groups?

• Bubble sort

• Merge sort

• Linear search

• Binary search

What algorithm does this image represent?

• Bubble sort

• Merge sort

• Linear search

• Binary search

What is a sorting algorithm?

• Specific instructions which allow us to understand code

• Specific instructions which allow us to organise data in a particular way

• Kinda like a word-scrambler

• Kinda like a password-decrypter

What is the most important reason that data needs to be sorted?

• It is organised and easier to make sense of.

• So it looks nice.

• To show we can do it.

How do merge sorts work?

• They split the list to single elements before piecing them back together, one sublist at a time.

• Each item in the list is compared with the following item starting with the last value till the first.

• Taking one item at a time from an unsorted list, each new item is compared with the previous until its place is found.

• Each item in the list is individually compared with the following item starting with the first value till the last.

The following two lists are to be merged, which element first goes into the new merged list?

List 1

2 4 7 9

List 2

1 6 8 12

• 0

• 1

• 2

• 3

The following two lists are to be merged, which element will be in position 5 in the new merged list?

List 1

2 4 7 9

List 2

1 6 8 12

• 8

• 7

• 6

• 4

For what purpose would a merge sort algorithm be used?

• To list items alphabetically.

• To reorder a single list.

• To combine identical lists together.

• To reorder multiple lists into a singular ordered list.

Where would a merge sort be used?

• To arrange files in a cupboard.

• To arrange data in a computer folder.

• To sort data on the fly.

• To sort data that is too large to store in memory.

What is an advantage of merge sorts?

• It can be applied to large data sets.

• It is completed quickly.

• It is computationally cheap.