Algorithms- Flowcharts

Flowcharts Basics

A flowchart is a type of diagram that represents an algorithm or process, showing the steps as boxes of various kinds, with their order by connecting them with arrows.
Flowcharts offer a visual way of representing algorithms. They are excellent tools for communicating how processes work, and for clearly documenting how a particular task is to be completed.
The different boxes (or ‘nodes’) represent different types of operation in the algorithm. The arrows direct the flow of operation – hence the name ‘flowchart’.

Common Symbols Used in Flowcharts

Ovals: Used to represent the start and end points of a process.
Rectangles: Demonstrate a process, or an operation. It’s an instruction for action.
Diamonds/Rhombus: Shows a decision point in the process. This is often a yes/no question or true/false test.
Arrows: Indicate the flow of control. An arrow coming from one symbol and ending at another symbol represents that control passes to the symbol where the arrow ends.

Creating Flowcharts

Start and finish your flowchart with the terminator (oval) symbol.
Use rectangles for processes that need to be completed, such as ‘Input username’.
Decisions are represented by diamonds – each decision will have at least two outcomes, which should also be clearly labelled.
Make sure your flowchart is logical and clear. Arrows should not cross over each other unnecessarily.

Evaluating Flowcharts

When evaluating a flowchart, check for clarity (Is each process and decision clear?); accuracy (Does it reflect the actual or intended process?); and efficiency (Are there unnecessary steps that could be removed or simplified?).
Flowcharts, like other forms of representing algorithms, can be reviewed and revised. Look to see if there are simpler or more efficient ways of reaching the same outcome.
Revisions to flowcharts should improve clarity, accuracy and efficiency without distorting the aim of the process or algorithm.

Using Flowcharts for Problem Solving

Flowcharts can be used to represent complex problems and associated algorithms visually, making them easier to understand.
They can illustrate potential options, paths and outcomes in decision-making processes.
By visualizing algorithms or processes, flowcharts can highlight potential issues or inefficiencies which might not be as obvious in other forms of representation.