<aside> 👀 EXAM QUESTION: Giving an example, describe the characteristics of a recursive sorting algorithm. (4 marks)

A recursive algorithm calls itself (1 mark) using a parameter (1 mark) and has a stopping condition (1 mark).

Example: quicksort (1 mark)

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Sorting data requires putting raw data into so pre-determined order, e.g. alphabetical, ascending or descending.

The type of Sorting Algorithm used depends on the following:

• Is the data in main memory
• Is it stored on disk
• The size of data to be sorted
• Speed and efficiency
• The amount of memory used.

Bubble sort

<aside> 💡 - Easy to program

• Simple to complete where there is a small dataset
• Very slow if the data set is large

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Steps

1.Start with the first pair of numbers I the list and compare N(0) with N(1)

2.If N(0) > N(1) then swap, i.e. N(0) becomes N(1) and N(1) becomes N(0). If a swap took place set a flag

3. Go on to the next pair of numbers and repeat stage 1 and 2 until the last pair of numbers have been compared.

4. Note if a swap has taken place then reset the flag and repeat the process. if no swap took place then end.

Algorithm

Start Procedure SortMyArray
    n Is Integer
    temp Is Integer
    swapped Is Boolean

    set n = length(myArray) {returns the length of myArray}
    repeat
        set swapped = FALSE
            for i = 0 to (n – 1)
                if myArray(i) < myArray(i + 1) then
                temp = myArray(i + 1)
                myArray(i + 1) = myArray(i)
                myArray(i) = temp
                swapped = TRUE
                end if
            end for
   until (swapped = FALSE)

Insertion sort