What is an algorithm?
An algorithm is a set of highly specific and organised instructions to be followed in order to carry out a task. A few examples of some very simple algorithms would be a following a medical prescription, brushing your teeth, putting a load of washing on, etc.
Another type of algorithm would be a recipe, telling you how to prepare a dish, step by step.
Going back to the asparagus, We will need to follow some instructions in order to cook it:
An easy way of representing an algorithm is by using a flow chart.
What is a flow chart?
Flow charts are diagrams used to give a clear and simple representation of a process, such as that of an algorithm. These are the basic elements that are represented in a flow chart:
|The start and end of the process.|
|The process or action executed starting from some data, which could be input, output or the result of a previous process.|
|The input and output data.|
|A condition or question that could have various paths: yes/no, true/false, greater than/less than, equal to/different to, etc.|
|The direction of the processes.|
Programming a countdown timer
A button must be created for each contestant on a television game show. So every time the host asks a question, the contestants have to press the button if they know the answer and a light will indicate who was the fastest. Once the button has been released, the light should switch off.
|First of all, we need to think about our algorithm, so that we can then create our flow chart:
TIP: Develop the flow chart for the proposed exercises before you start programming. Then you´ll see how much it easier it is to resolve them.
And there´s more
- Here´s a few more ideas so you can keep on practising:
- Write a simple algorithm down on paper for an everyday activity (sending a letter, making a phone call, getting ready to go to work, etc.)
- Then rewrite the same algorithm, but with maximum detail in the instructions to enable someone else to carry them out.
Every time you´re faced with a problem, ask yourself these two questions: What do I need to do? How can I do it? The algorithms and diagrams can be really useful for outlining the solution to a problem. So now you know this, make sure you always have pen and paper to hand!