PRL1013 Problem Solving: Flowchart & Algorithms

Course Information

• Course title: PRL1013 Problem Solving in Computing
• Learning Unit 3: Designing the Solution
• Lecturers: Michelle Anak George, Eaqerzilla Phang, Dr Sinarwati Binti Mohamad Suhaili

Agenda

• Sub-topics covered: Flowchart, Pseudocode, Algorithm

Flowchart

• Definition (Dictionary): A schematic representation of a sequence of operations in a computer program or manufacturing process.
• Definition (Technical): A graphical representation of the sequence of operations in an information system or program.
• Information System Flowcharts: Illustrate data flow from source documents through computers to end-users.
• Program Flowcharts: Detail the sequence of instructions within a program or subroutine.
• Symbol Usage: Different flowchart symbols are used to represent various tasks (oval for start/end, parallelogram for input/output, rectangle for processes, diamond for decisions, etc.).

Flowchart Example

• Calculating a student's final grade: Determines whether a student's grade (average of four marks) is passing or failing.

Flowcharts Symbols

• Oval: Beginning or end of the program.
• Parallelogram: Input or output operation.
• Rectangle: Process to be carried out (e.g., calculation).
• Diamond: Decision point, two possible routes.
• Hybrid: Output operation.
• Flow Line: Direction of logical flow in the program.

Example Scenarios and Solutions

• Example 1: Algorithm to determine a student's final grade:
  • Input marks M1, M2, M3, M4.
  • Calculate GRADE = (M1 + M2 + M3 + M4) / 4.
  • If GRADE < 50, then print "FAIL"; else print "PASS".
• Example 2: Converting length from feet to centimeters:
  • Input length in feet (Lft).
  • Calculate length in cm (Lcm) = Lft x 30.
  • Print Lcm.
• Example 3: Calculating the area of a rectangle:
  • Input width (W) and length (L).
  • Calculate area (A) = L x W.
  • Print A.

Flowchart Symbols (Basic)

• Basic flowchart shapes and their purpose.

Flowcharts - Sequence Control Structure

• Shows the steps executed in order.

Flowcharts - Selection Control Structure

• Represents decision-making processes with conditions

Flowcharts - Repetition Control Structure

• Used to repeat a set of instructions for a certain number of times or till a condition ceases to be true.

Flowchart Example 1

• Algorithm for calculating age

Flowchart Example 2

• Algorithm for determining if someone is eligible for retirement.

Flowchart Example 3

• Algorithm for calculating the sum of numbers from 1 to 10.

General Flowchart Concepts

• Flowcharts are graphical representations that aid in visualizing program logic step-by-step.
• They use geometric shapes connected by lines to depict the operations and decisions.
• They offer an alternative to pseudocode, which is textual, allowing for a visual representation of an algorithm.

Flowchart - Additional Symbols

• Terminal symbol.
• Process symbol.
• Input-output symbol.
• Disk storage I/O symbol.
• Printer output symbol.
• Selection symbol for a two-way decision.
• Off-page connector.
• On-page connector.
• Flow lines.

Evaluate your understanding of flowcharts, pseudocode, and algorithms with this quiz from Learning Unit 3 of PRL1013. You'll explore the definitions, symbol usage, and practical examples of designing solutions in computing. Test your knowledge and enhance your problem-solving skills!