Algorithm is a step – by – step procedure which is helpful in solving a problem. If, it is written in English like sentences then, it is called as ‘PSEUDO CODE’.
Properties of an Algorithm
An algorithm must possess the following five properties −
- Input
- Output
- Finiteness
- Definiteness
- Effectiveness
Example
Algorithm for finding the average of three numbers is as follows −
- Start
- Read 3 numbers a,b,c
- Compute sum = a+b+c
- Compute average = sum/3
- Print average value
- Stop
FLOW CHART
Diagrammatic representation of an algorithm is called flow chart.
Symbols used in flowchart are mentioned below −
| Name | Symbol | Purpose |
|---|---|---|
| Terminal |  Oval | start/stop/begin/end |
| Input/output |  Parallelogram | Input/output of data |
| Process |  Rectangle | Any processing to be performaed can be represented |
| Decision box |  Diamon | Decision operation that determine which of the alternative paths to be followed |
| Connector |  Circle | Used to connect different parts of flowchart |
| Flow |  Arrows | Join 2 symbols and also represents flow of execution |
| Pre defined process |  Double Sided Rectangle | Module (or) subroutines specified else where |
| Page connector |  Pentagon | Used to connect flowchart in 2 different pages |
| For loop symbol |  Hexagon | shows initialization, condition and incrementation of loop variable |
| Document |  Printout | Shows the data that is ready for printout |
Example
Given below is the flowchart for finding an average of three numbers −
