In this chapter, we examine a number of standard algorithms, introduce some new data structures, examine file processing and then consider some problems requiring custom-designed logic. 

We then consider the design of the user interface, followed by factors to consider when selecting a suitable programming language. 

Finally we consider benchmarking as a technique for assessing different technologies.

What is an algorithm?

An algorithm is a method of solution for a problem. Algorithms describe the steps taken to transform inputs into the required outputs. 

Each algorithm will have a distinct start and end, and will be composed of the three control structures: sequence, decision and repetition. 

Algorithms are described using an algorithm description language; in this course we use either pseudocode or flowcharts. Pseudocode and flowcharts provide a language in which we can express algorithms.

Student Activity

Answer the following questions:

• Explain the difference between a function and a procedure
• What are the two 'languages' of algorithms that we use in the HSC
• Explain top - down design