Flowchart and Algorithm

Flowchart

A flowchart is a pictorial (graphical) representation of an algorithm. A flowchart is drawn using different kinds of symbols. A symbol is used for a specific purpose. Each symbol has name.

Flowcharts use different shapes of boxes to denote different type of instructions. ANSI recommended a number of different rules and guidelines to help standardize the flowcharting process.

• Algorithms are represented using flowcharts
• Flowchart symbols are standardized by ANSI
• Flowchart helps to divide a large complex problem into small manageable ones
• Generally, algorithm is first represented as a flowchart and then expressed in a programming
  language
• While preparing a flowchart, the sequence, selection and iterative structures may be used wherever
  required

Note

Experienced programmers, sometimes write programs without drawing a flowchart. Beginners should first draw a flowchart to reduce number of errors in the program.

Rules for Drawing a Flowchart

• It should contain only one start and one end symbol
• The relevant symbols must be used while drawing a flowchart
• The direction of arrows should be top to bottom and left to right
• It should be simple and drawn clearly and neatly
• Be consistent in using names, variables in the flow chart
• Use properly labeled connectors to link the portions of the flowchart on different pages
• The branches of decision box must be label

Advantages of Flowcharts

• Conveys better meaning
• Analyses the problem effectively
• Good tool for documentation
• Provide guide for coding
• Systematic debugging
• Systematic testing

Disadvantages of Flowcharts

• Takes more time to draw. Imagine developing a detailed flowchart for a program containing 50000
  lines or statements of instructions
• Difficult to make changes
• Non-standardization – No standards to determine amount of details should be included in a flowchart