LECTURE 10: Algorithm Design: Pseudocode and Flowcharts

Pseudocode:

• Description of an algorithm using structured English
• Allows the user to focus on the logic of the algorithm without being distracted by the details of the language syntax

Flowchart

• Allows schematic representation of an algorithm

Example: Program that reads the score and prints grade ‘A’ if score > 60, and grade ‘F’ if score < 60.

Pseudocode:

Begin

enter score

if score > 60

grade = ‘A’

else

grade = ‘F’

print grade

End

Flowchart:

Advanced Topics from Chapter 5

Compound Assignment Operator

variable op = expression;

is the same as

variable = variable op (expression)

where

op is +, -, *, /, %

Example:

i += 3;

is the same as

i = i + 3;

Increment/Decrement Operators

Given integer or double variable x:

x++;

is the same as

x = x + 1;

++x;

is the same as

x = x + 1;

x--;

is the same as

x = x-1;

--x;

is the same as

x = x-1;

The difference between x++ and ++x

• read p.224-226 from the textbook