Description

Problems for exercises and homework for the “C# OOP” course @ SoftUni”.
You can check your solutions here: https://judge.softuni.bg/Contests/1498/Encapsulation-Exercise
Problem 1. Class Box Data
You are given a geometric figure box with parameters length, width and height. Model a class Box that that can be instantiated by the same three parameters. Expose to the outside world only methods for its surface area, lateral surface area and its volume (formulas: http://www.mathwords.com/r/rectangular_parallelepiped.htm).
A box’s side should not be zero or a negative number. Аdd data validation for each parameter given to the constructor. Make a private setter that performs data validation internally.
Input
• On the first three lines you will get the length, width and height.
Output
• On the next three lines print the surface area, lateral surface area and the volume of the box:
Examples
Input Output
2
3
4 Surface Area – 52.00
Lateral Surface Area – 40.00
Volume – 24.00
1.3
1
6 Surface Area – 30.20
Lateral Surface Area – 27.60
Volume – 7.80
2
-3
4 Width cannot be zero or negative.

Problem 2. Animal Farm
For this problem you have to download the provided skeleton.
You should be familiar with encapsulation already. For this problem, you’ll be working with the Animal Farm project.
It contains a class Chicken. Chicken contains several fields, a constructor, several properties and several methods. Your task is to encapsulate or hide anything that is unintended for viewing or modification from outside the class.
Step 1. Encapsulate Fields
Fields should be private. Leaving fields open for modification from outside the class is potentially dangerous. Make all fields in the Chicken class private. In case the value inside the field is needed elsewhere, use getters to reveal it.
Step 2. Ensure Classes Have a Correct State
Having getters and setters is useless, if you don’t actually use them. The Chicken constructor modifies the fields directly, which is wrong when there are suitable setters available. Modify the constructor to fix this issue.
Step 3. Validate Data Properly
Validate the chicken’s name (it cannot be null, empty or whitespace). In case of invalid name, print exception message: “Name cannot be empty.” .
Validate the age properly, minimum and maximum age are provided, make a use of them. In case of an invalid age, print exception message: “Age should be between 0 and 15.”. Don’t forget to handle properly the possibly thrown exceptions.
Step 4. Hide Internal Logic
If a method is intended to be used only by descendant classes or internally to perform some action, there is no point in keeping them public. The CalculateProductPerDay() method is used by the ProductPerDay public getter. This means the method can safely be hidden inside the Chicken class by declaring it private.
Step 5. Submit Code to Judge
Submit your code as a zip file in Judge. Zip everything except the bin and obj folders within the project and submit the single zip file in judge.
Examples
Input Output
Mara 10 Chicken Mara (age 10) can produce 1 eggs per day.
Mara 17 Age should be between 0 and 15.
Problem 3. Shopping Spree
Create two classes: class Person and class Product. Each person should have a name, money and a bag of products.
Each product should have a name and a cost. Name cannot be an empty string. Money cannot be a negative number.
Create a program in which each command corresponds to a person buying a product. If the person can afford a product, add it to his bag. If a person doesn’t have enough money, print an appropriate message (“[Person name] can’t afford [Product name]”).
On the first two lines you are given all people and all products. After all purchases print every person in the order of appearance and all products that he has bought also in order of appearance. If nothing was bought, print the name of the person followed by “Nothing bought”.
In case of invalid input (negative money exception message: “Money cannot be negative”) or an empty name (empty name exception message: “Name cannot be empty”) break the program with an appropriate message. See the examples below:
Examples
Input Output
Pesho=11;Gosho=4
Bread=10;Milk=2;
Pesho Bread
Gosho Milk
Gosho Milk
Pesho Milk
END Pesho bought Bread
Gosho bought Milk
Gosho bought Milk
Pesho can’t afford Milk
Pesho – Bread
Gosho – Milk, Milk
Mimi=0
Kafence=2
Mimi Kafence
END Mimi can’t afford Kafence Mimi – Nothing bought
Jeko=-3
Chushki=1;
Jeko Chushki
END Money cannot be negative
Problem 4. Pizza Calories
A Pizza is made of dough and different toppings. You should model a class Pizza, which should have a name, dough and toppings as fields. Every type of ingredient should have its own class. Every ingredient has different properties: the dough can be white or wholegrain and in addition, it can be crispy, chewy or homemade. The toppings can be of type meat, veggies, cheese or sauce. Every ingredient should have a weight in grams and a method for calculating its calories according to its type. Calories per gram are calculated through modifiers. Every ingredient has 2 calories per gram as a base and a modifier that gives the exact calories. For example, a white dough has a modifier of 1.5, a chewy dough has a modifier of 1.1, which means that a white chewy dough, weighting 100 grams will have 2 * 100 *
1.5 * 1.1 = 330.00 total calories.
Your job is to model the classes in such a way that they are properly encapsulated and to provide a public method for every pizza that calculates its calories according to the ingredients it has.
Step 1. Create a Dough Class
The base ingredient of a Pizza is the dough. First, you need to create a class for it. It has a flour type, which can be white or wholegrain. In addition, it has a baking technique, which can be crispy, chewy or homemade. A dough should have a weight in grams. The calories per gram of a dough are calculated depending on the flour type and the baking technique. Every dough has 2 calories per gram as a base and a modifier that gives the exact calories. For example, a white dough has a modifier of 1.5, a chewy dough has a modifier of 1.1, which means that a white chewy dough, weighting 100 grams will have (2 * 100) * 1.5 * 1.1 = 330.00 total calories. You are given the modifiers below:
Modifiers:
• White – 1.5;
• Wholegrain – 1.0;
• Crispy – 0.9;
• Chewy – 1.1;
• Homemade – 1.0;
Everything that the class should expose is a getter for the calories per gram. Your task is to create the class with a proper constructor, fields, getters and setters. Make sure you use the proper access modifiers.
Step 2. Validate Data for the Dough Class
Change the internal logic of the Dough class by adding a data validation in the setters.
Make sure that if invalid flour type or an invalid baking technique is given a proper exception is thrown with the message “Invalid type of dough.”.
The allowed weight of a dough is in the range [1..200] grams. If it is outside of this range throw an exception with the message “Dough weight should be in the range [1..200].”.
Exception Messages
• “Invalid type of dough.”
• “Dough weight should be in the range [1..200].”
Make a test in your main method that reads Doughs and prints their calories until an “END” command is given.
Examples
Input Output
Dough White Chewy 100 END 330.00
Dough Tip500 Chewy 100 END Invalid type of dough.
Dough White Chewy 240 END Dough weight should be in the range [1..200].
Step 3. Create a Topping Class
Next, you need to create a Topping class. It can be of four different types – meat, veggies, cheese or a sauce. A topping has a weight in grams. The calories per gram of topping are calculated depending on its type. The base calories per gram are 2. Every different type of topping has a modifier. For example, meat has a modifier of 1.2, so a meat topping will have 1.2 calories per gram (1 * 1.2). Everything that the class should expose is a getter for calories per gram. You are given the modifiers below:
Modifiers:
• Meat – 1.2;
• Veggies – 0.8;
• Cheese – 1.1;
• Sauce – 0.9;
Your task is to create the class with a proper constructor, fields, getters and setters. Make sure you use the proper access modifiers.
Step 4. Validate Data for the Topping Class
Change the internal logic of the Topping class by adding a data validation in the setter.
Make sure the topping is one of the provided types, otherwise throw a proper exception with the message “Cannot place [name of invalid argument] on top of your pizza.”.
The allowed weight of a topping is in the range [1..50] grams. If it is outside of this range throw an exception with the message “[Topping type name] weight should be in the range [1..50].”.
Exception Messages
• “Cannot place [name of invalid argument] on top of your pizza.”
• “[Topping type name] weight should be in the range [1..50].”
Make a test in your main method that reads a single dough and a topping after that and prints their calories.
Examples
Input Output
Dough White Chewy 100
Topping meat 30
END 330.00 72.00
Dough White chewy 100
Topping Krenvirshi 500
END 330.00
Cannot place Krenvirshi on top of your pizza.
Dough White Chewy 100
Topping Meat 500
END 330.00
Meat weight should be in the range [1..50].
Step 5. Create a Pizza Class!
A Pizza should have a name, some toppings and a dough. Make use of the two classes you made earlier. In addition, a pizza should have public getters for its name, number of toppings and the total calories. The total calories are calculated by summing the calories of all the ingredients a pizza has. Create the class using a proper constructor, expose a method for adding a topping, a public setter for the dough and a getter method for the total calories.
The input for a pizza consists of several lines. On the first line is the pizza name and on the second line, you will get input for the dough. On the next lines, you will receive every topping the pizza has.
If the creation of the pizza was successful, print on a single line the name of the pizza and the total calories it has.
Step 6. Validate Data for the Pizza Class
The name of the pizza should not be an empty string. In addition, it should not be longer than 15 symbols. If it does not fit, throw an exception with the message “Pizza name should be between 1 and 15 symbols.”.
The number of toppings should be in range [0..10]. If not, throw an exception with the message “Number of toppings should be in range [0..10].”.
Your task is to print the name of the pizza and the total calories it has according to the examples below.
Examples
Input Output
Pizza Meatless
Dough Wholegrain Crispy 100
Topping Veggies 50
Topping Cheese 50
END Meatless – 370.00 Calories.
Pizza Burgas
Dough White Homemade 200
Topping Meat 123
END Meat weight should be in the range [1..50].
Pizza Bulgarian
Dough White Chewy 100
Topping Sauce 20
Topping Cheese 50
Topping Cheese 40
Topping Meat 10
Topping Sauce 10
Topping Cheese 30
Topping Cheese 40
Topping Meat 20
Topping Sauce 30
Topping Cheese 25
Topping Cheese 40
Topping Meat 40
END Number of toppings should be in range [0..10].
Pizza Bulgarian
Dough White Chewy 100
Topping Sirene 50
Topping Cheese 50
Topping Krenvirsh 20
Topping Meat 10
END Cannot place Sirene on top of your pizza.
Problem 5. **Football Team Generator
A football team has variable number of players, a name and a rating. A player has a name and stats, which are the basis for his skill level. The stats a player has are endurance, sprint, dribble, passing and shooting. Each stat can be an integer in the range [0..100]. The overall skill level of a player is calculated as the average of his stats. Only the name of a player and his stats should be visible to the entire outside world. Everything else should be hidden.
A team should expose a name, a rating (calculated by the average skill level of all players in the team and rounded to the integer part only) and methods for adding and removing players.
Your task is to model the team and the players following the proper principles of Encapsulation. Expose only the properties that need to be visible and validate data appropriately.
Input
Your application will receive commands until the “END” command is given. The command can be one of the following:
• “Team;{TeamName}” – add a new team;
• “Add;{TeamName};{PlayerName};{Endurance};{Sprint};{Dribble};{Passing};{Shooting}” – add a new player to the team;
• “Remove;{TeamName};{PlayerName}” – remove the player from the team;
• “Rating;{TeamName}” – print the team rating, rounded to an integer.
Data Validation
• A name cannot be null, empty or white space. If not, print “A name should not be empty.”
• Stats should be in the range 0..100. If not, print “[Stat name] should be between 0 and 100.”
• If you receive a command to remove a missing player, print “Player [Player name] is not in [Team name] team.”
• If you receive a command to add a player to a missing team, print “Team [team name] does not exist.”
• If you receive a command to show stats for a missing team, print “Team [team name] does not exist.”
Examples
Input Output
Team;Arsenal
Add;Arsenal;Kieran_Gibbs;75;85;84;92;67
Add;Arsenal;Aaron_Ramsey;95;82;82;89;68
Remove;Arsenal;Aaron_Ramsey
Rating;Arsenal
END Arsenal – 81
Team;Arsenal
Add;Arsenal;Kieran_Gibbs;75;85;84;92;67
Add;Arsenal;Aaron_Ramsey;195;82;82;89;68
Remove;Arsenal;Aaron_Ramsey
Rating;Arsenal
END Endurance should be between 0 and 100. Player Aaron_Ramsey is not in Arsenal team. Arsenal – 81
Team;Arsenal
Rating;Arsenal
END Arsenal – 0