Estruturas Condicionais 2 - Curso de Algoritmos #08 - Gustavo Guanabara

Conditional Structures in Algorithms: Part 2

Introduction to Nested Conditionals

• Gustavo Guanabara introduces the lesson on conditional structures, focusing on nested conditionals and choice structures, building upon previous lessons.

• The importance of following the course sequentially is emphasized for better understanding.

Understanding Conditional Scenarios

• A simple example of a conditional structure is presented: "If I have a lot of money, I'll go to Disney; otherwise, I'll stay home."

• Real-life scenarios often involve multiple choices. For instance, having different amounts of money leads to various travel options beyond just two outcomes.

Implementation of Nested Conditionals

• The concept of nested conditionals is introduced with an algorithmic approach using Visualg. It illustrates how one conditional can exist within another.

• An example code snippet demonstrates how to check financial conditions and decide between going to Disney or staying home based on available funds.

Practical Application: Student Evaluation

• A practical scenario involving student evaluation (approved, disapproved, or in recovery) is discussed as a real-world application of nested conditionals.

• The algorithm begins by asking for two student grades and calculating their average while ensuring proper order in operations.

Evaluating Student Performance

• Conditions are set for determining if a student passes (average ≥ 7), fails, or is in recovery (average between 5 and 7).

• The logic flow includes checking multiple conditions using nested statements to accurately reflect the student's status based on their average grade.

Conclusion and Further Exploration

• The importance of indentation in coding for clarity when dealing with nested structures is highlighted.

Understanding BMI Calculation and Conditional Structures in Programming

Introduction to BMI Ranges

• The previous class focused on calculating Body Mass Index (BMI) to determine if individuals fall within the ideal weight range, highlighting various categories from underweight to morbid obesity.

• The current session aims to refine the algorithm by eliminating unnecessary conditional structures while maintaining accurate BMI calculations.

Implementing Nested Conditionals

• The calculation of BMI is defined as weight divided by height squared. Initial focus will be on categorizing individuals based on their BMI values.

• A nested conditional structure will be used, with tips for code organization:

• Keep code indented for clarity.

• Always close an 'if' statement with 'End If' to avoid errors.

Defining Weight Categories

• Conditions are set for different BMI ranges:

• Very Underweight: BMI < 17 results in "Very underweight".

• Underweight: 17 ≤ BMI ≤ 18.5 results in "Under weight".

• Additional conditions include:

• Ideal Weight: 18.5 ≤ BMI < 25 results in "ideal weight".

• Overweight: 25 ≤ BMI < 30 results in "Overweight".

Advanced Obesity Classifications

• Further classifications include:

• Obesity: 30 ≤ BMI < 35.

• Severe Obesity: 35 ≤ BMI < 40.

• Finally, any individual with a BMI ≥ 40 is classified as having morbid obesity.

Testing the Algorithm

• The instructor demonstrates testing the algorithm using various weights and heights, confirming that it accurately categorizes individuals based on their calculated BMIs.

• Examples include:

• A person weighing 40 kg at a height of two meters has a low BMI.

• A person weighing over200 kg at one meter tall falls into morbid obesity.

Exploring Alternative Conditional Structures

• An introduction to another useful conditional structure called "choice" is presented, which simplifies decision-making processes in programming.

• This structure allows for selecting cases based on variable input without complex nested conditions.

Practical Application of Choice Structure

• An example program titled “Child Hope” illustrates how donations can be processed using the choice structure:

• Users select donation amounts or cancel their donation through simple case statements.

Conclusion and Program Execution

• The program concludes by thanking users for their contributions and displaying the total amount donated based on user input selections.

Conditional Structures in Programming

Understanding Conditional Structures

• The choice of structure in programming does not test a range of values but rather checks specific conditions, such as greater than or equal to, or less than. This is primarily applicable for integer values.

• It is advised to use only integer values with conditional structures; they are not universally applicable across all situations.

Example Algorithm: Employee Salary Calculation

• An example algorithm prompts the user for an employee's name, salary, and number of dependents. Variables include name (character type), salary (real type), and dependents (integer).

• If an employee has no dependents, their salary increases by 5%. The calculation involves multiplying the salary by 5% and adding it to the original salary.

• For employees with 1 to 3 dependents, there is a 10% increase; with 4 to 6 dependents, a 15% increase; and more than 6 dependents results in an 18% increase.

Salary Calculation Examples

• Using a fixed salary of $1000 for simplicity:

• José has three dependents and receives a new salary of $1100 after a 10% increase.

• Maria has no dependents and only receives a $50 raise (5%).

• André earns $1000 with five dependents resulting in a new salary of $1150 due to the 15% increase.

• Claudia earns $1000 with nine dependents, leading to an increased salary of $1180 after an 18% raise.

Summary of Conditional Structures

• The lesson concludes by summarizing various conditional structures discussed throughout the course: simple conditionals, composite conditionals, lined conditionals, and case choices.

Proposed Exercises

Student Grade Classification Exercise

• An exercise involves calculating student grades based on averages:

• A: Average between 9 and 10

• B: Average between 8 and <9

• C: Average between 7 and <8

• D: Average between 6 and <7

• E: Average between 5 and <6

• F: Below average of <5

Football Match Analysis Exercise

• Another exercise analyzes football match outcomes based on goals scored:

• Different scenarios are presented based on goal differences that determine win/loss/tie situations.

Conclusion & Next Steps

• The lesson wraps up by emphasizing understanding conditional structures before moving on to repetition structures in future lessons.

Sign Up and Course Access

Course Enrollment Process

• To enroll in the course, users need to click on a specific link to sign up. This process includes authorizing the receipt of emails.

• After signing up, students gain access to all classes organized into playlists available on cursoemvideo.com.

• The course "Algorithm" is highlighted, with answers provided one week after each lesson's availability.

Practice and Answer Availability

• Students have a week to practice before viewing the answers; this encourages independent problem-solving.

• Answers for class 8 will be released alongside those for class 7, ensuring that students who follow the weekly schedule can benefit from timely assistance.