Flowcharting Guidelines http://www.nos.org/htm/basic2.htm Flowcharting Guidelines

What is a flowchart? A diagrammatic representation that illustrates the sequence of operations to be performed to get the solution of a problem. Flowcharts are generally drawn in the early stages of formulating computer solutions. Flowcharts facilitate communication between programmers and business people. Plays a vital role in the programming of a problem and are quite helpful in understanding the logic of complicated and lengthy problems.

Guidelines in flowcharting All necessary requirements should be listed out in logical order Flowchart should be clean, neat and easy to follow; no room for ambiguity in understanding the flowchart Usual direction of the flow is from left to right, or top to bottom Only one flow line should come out from a process symbol

Guidelines Only one flow line should enter a decision symbol, but two or three flow lines, one for each possible answer, should leave the decision symbol Only one flow line is used in conjunction with the terminal symbol If the flowchart becomes complex, it is better to use connector symbols to reduce the number of flow lines. Avoid intersection of flow lines if you want to make it more effective.

Guidelines Ensure that the flowchart has a logical start and finish It is useful to test the valid of the flowchart by passing through it with a test data.

Example 1: Draw a flowchart to find the sum of the first 50 numbers

Example 2: See this flowchart and its equivalent pseudocode

Compute the sum, average and product of three numbers:

Switching logic (Decisions) Switching logic consists of two components – a condition and a goto command depending on the result of the condition test. The computer can determine the truth value of a statement involving one of six mathematical relations symbolized in the table on the next slide: SOURCE: http://www.allclearonline.com/applications/DocumentLibraryManager/upload/program_intro.pdf

Mathematical symbols

A step in an algorithm that leads to more than one possible continuation is called a decision.

Example 3: Flowchart for a program that reads two numbers and displays the numbers in decreasing order:

Example 4: Find the largest of three numbers A, B and C