Paper 2 Revision

An algorithm to sort data is shown in the image. State the name of the sorting algorithm

What is an example of a 'defensive design consideration'?

• Comments or indentation in code

• Syntax errors or Boolean operators

• Iterative or final testing

• Handling exceptions in programs

Checking data input by the user meets specific criteria before processing is the definition for which key term?

• Syntax error

• Validation

• Verification

• Authentication

State the equivalent Boolean expression for this circuit diagram.

• X = A OR (C AND NOT B)

• Y = (C AND NOT B) OR A

• A = (NOT B AND C) OR A

• Z = (NOT B AND C) OR A

Which flowchart symbol is used to signify an output?

Pick all the statements that define a merge sort.

• a divide and conquer algorithm

• a list is repeatedly divided into smaller lists eventually containing just one item

• two lists are merged together into four

• each element is compared with the adjacent list

Select all the characteristics of a binary search

• Starts from the calculated middle position

• if the item is not found, quarter of the data set can be discarded

• the data set must be sorted first

• algorithm repeats until the data item is found or no items are left to check

Select all that describe iterative testing

• testing is carried out during development of the code

• each new sub program is checked for errors

• testing is carried out once the program has been compiled

• testing checks to see if new code written has broken existing code or introduced new errors

The program in the image should output the word Computing ten times but it does not work. Correct the error.

Identify two reasons why programs might need refining.

• Code maybe efficient

• Code maybe inefficient

• repeated code may be put into subprograms or loops

• repeated code may be put into selection statements