Untitled Quiz

Course Information

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

Agenda

• Flowchart
• Pseudocode
• Algorithm

What is a Flowchart

• A flowchart is a schematic representation of a sequence of operations in a computer program or manufacturing process.
• It's a graphical representation of the sequence of steps in an information system or program.
• Information system flowcharts show the flow of data from source documents through the computer to users.
• Program flowcharts illustrate the sequence of instructions within a single program or subroutine.
• Several symbols are used to represent different actions in the flowchart.

The Flowchart

• A flowchart displays the logic of an algorithm and the interactions between different steps.
• Flowcharts specifically emphasize the step-by-step interactions between individual steps or actions, and the connections between them, explaining the control flow from one action to the next.

Flowchart Symbols - Basic

• Oval: Denotes the beginning or end of a program.
• Parallelogram: Represents an input operation.
• Rectangle: Indicates a process, such as addition, subtraction, or division.
• Diamond: Indicates a decision point; the program branches to one of two routes.
• Hybrid: Represents an output operation.
• Flow line: Shows the direction of logical flow in the program.

Example Scenario 1

• An algorithm to determine a student's final grade (calculated as the average of four marks), and whether it is passing or failing.

Example Solution 1

• Step 1: Input four marks (M1, M2, M3, M4).
• Step 2: Calculate the grade as the average of the four marks. (GRADE = (M1 + M2 + M3 + M4)/4)
• Step 3: Check if the grade is less than 50.
  • If yes, print "FAIL".
  • If no, print "PASS".

Example Scenario 2

• Write an algorithm and flowchart to convert length in feet to centimeters.
• Pseudocode:
  • Input the length in feet (Lft).
  • Calculate the length in centimeters (Lcm) by multiplying Lft by 30.
  • Print the length in centimeters (Lcm).

Example Solution 2

• Step 1: Input Lft.
• Step 2: Calculate Lcm by multiplying Lft by 30.
• Step 3: Print Lcm.

Example Solution 3

• Algorithm for Finding Area of a Rectangle:
• Step 1: Input the Width (W) and Length (L) of the rectangle.
• Step 2: Calculate the area (A) by multiplying L with W. (A = L x W)
• Step 3: Print the area A

Flowcharts (General)

• Flowcharts are graphical representations of step-by-step solutions.
• They use different geometrical shapes for various steps (e.g., start/end, input/output, process, decision).
• Flowcharts are connected with flow lines to illustrate the sequence of operations.
• They are an alternative method to pseudocode, where pseudocode is textual, flowcharts are visual.

Flowchart Symbols (Specific)

• Terminal: Marks the start and end of an algorithm.
• Process: Represents a general step in an algorithm.
• Input/Output: Used for input or output operations.
• Disk Storage I/O: Represents data input or output from the disk.
• Printer Output: Shows hard copy printer output.
• Selection: Represents a decision-making point with two possible paths (if/else).
• Off-page Connector: For continuing logic across multiple pages.
• On-page Connector: For continuing from one point in the same flowchart page.
• Flow Lines: Indicate the sequence in the algorithm.

Additional details from the flowchart examples

• Basic flowchart structures are: sequence, selection, repetition
• Example flowcharts provide visual solutions for various algorithmic problems.