Description

Problems for exercises and homework for the “C# OOP” course @ SoftUni”.
You can check your solutions here: https://judge.softuni.bg/Contests/1502/Interfaces-and-Abstraction-Exercise
Problem 1. Define an Interface IPerson
NOTE: You need a public StartUp class with the namespace PersonInfo.
Define an interface IPerson with properties for Name and Age. Define a class Citizen which implements IPerson and has a constructor which takes a string name and an int age.
Try to create a new Person like this:
string name = Console.ReadLine(); int age = int.Parse(Console.ReadLine()); IPerson person = new Citizen(name, age);
Console.WriteLine(person.Name); Console.WriteLine(person.Age);
Examples
Input Output
Pesho
25 Pesho
25
Problem 2. Multiple Implementation
NOTE: You need a public StartUp class with the namespace PersonInfo.
Using the code from the previous task, define an interface IIdentifiable with a string property Id and an interface IBirthable with a string property Birthdate and implement them in the Citizen class. Rewrite the Citizen constructor to accept the new parameters.
Test your class like this:
string name = Console.ReadLine(); int age = int.Parse(Console.ReadLine()); string id = Console.ReadLine(); string birthdate = Console.ReadLine();
IIdentifiable identifiable = new Citizen(name, age,id, birthdate);
IBirthable birthable = new Citizen(name, age, id, birthdate);
Console.WriteLine(identifiable.Id);
Console.WriteLine(birthable.Birthdate);
Examples
Input Output
Pesho
25 9105152287
9105152287
Problem 3. Ferrari
Your task is to create a Ferrari and set the driver’s name to the passed one in the input. After that, print the info. Take a look at the Examples to understand the task better.
Input
On the single input line, you will be given the driver’s name.
Output
On the single output line, print the model, the messages from the brakes and gas pedal methods and the driver’s name. In the following format:
{model}/{brakes}/{gas pedal}/{driver’s name} Constraints
Example
Input Output
George 488-Spider/Brakes!/Gas!/George
Peter 488-Spider/Brakes!/Gas!/Peter
Problem 4. Telephony
You have a business – manufacturing cell phones. But you have no software developers, so you call some friends of yours and ask them to help you create a cell phone software. They have already agreed and you started working on the project. The project consists of one main model – a Smartphone. Each of your smartphones should have functionalities of calling other phones and browsing in the world wide web.
These friends of yours though are very busy, so you decide to write the code on your own. Here is the mandatory assignment:
You should have a model – Smartphone and two separate functionalities which your smartphone has – to call other phones and to browse in the world wide web. You should end up with one class and two interfaces.
Input
The input comes from the console. It will hold two lines:
• First line: phone numbers to call (string), separated by spaces.
• Second line: sites to visit (string), separated by spaces.
Output
• First call all numbers in the order of input then browse all sites in order of input
• The functionality of calling phones is printing on the console the number which are being called in the format:
Calling… {number}
• The functionality of the browser should print on the console the site in format:
Browsing: {site}!
• If there is a number in the input of the URLs, print: “Invalid URL!” and continue printing the rest of the URLs.
• If there is a character different from a digit in a number, print: “Invalid number!” and continue to the next number.
Constraints
• Each site’s URL should consist only of letters and symbols (No digits are allowed in the URL address)
Examples
Input Output
0882134215 0882134333 08992134215 0558123 3333 1 http://softuni.bg http://youtube.com http://www.g00gle.com Calling… 0882134215
Calling… 0882134333
Calling… 08992134215
Calling… 0558123
Calling… 3333
Calling… 1
Browsing: http://softuni.bg!
Browsing: http://youtube.com!
Invalid URL!
Problem 5. Border Control
It’s the future, you’re the ruler of a totalitarian dystopian society inhabited by citizens and robots, since you’re afraid of rebellions you decide to implement strict control of who enters your city. Your soldiers check the Ids of everyone who enters and leaves.
You will receive an unknown amount of lines from the console until the command “End” is received, on each line there will be a piece of information for either a citizen or a robot who tries to enter your city in the format:
“{name} {age} {id}” for citizens and “{model} {id}” for robots. After the end command on the next line you will receive a single number representing the last digits of fake ids, all citizens or robots whose Id ends with the specified digits must be detained.
The output of your program should consist of all detained Ids each on a separate line in the order of input.
Input
The input comes from the console. Every commands’ parameters before the command “End” will be separated by a single space.
Examples
Input Output
Pesho 22 9010101122
MK-13 558833251
MK-12 33283122
End
122 9010101122
33283122

Toncho 31 7801211340
Penka 29 8007181534
IV-228 999999
Stamat 54 3401018380
KKK-666 80808080
End
340 7801211340

Problem 6. Birthday Celebrations
It is a well known fact that people celebrate birthdays, it is also known that some people also celebrate their pets’ birthdays. Extend the program from your last task to add birthdates to citizens and include a class Pet, pets have a name and a birthdate. Encompass repeated functionality into interfaces and implement them in your classes.
You will receive from the console an unknown amount of lines. Until the command “End” is received, each line will contain information in one of the following formats “Citizen <name> <age> <id> <birthdate>” for citizens, “Robot <model> <id>” for robots or “Pet <name> <birthdate>” for pets. After the “End” command on the next line you will receive a single number representing a specific year, your task is to print all birthdates (of both citizens and pets) in that year in the format day/month/year in the order of input.
Examples
Input Output
Robot MK-13 558833251
End
Robot MK-10 12345678
Robot PP-09 00000001
End
Robot VV-XYZ 11213141
End <empty output>
1975
Problem 7. Food Shortage
Your totalitarian dystopian society suffers a shortage of food, so many rebels appear. Extend the code from your previous task with new functionality to solve this task.
Define a class Rebel which has a name, age and group (string), names are unique – there will never be 2
Rebels/Citizens or a Rebel and Citizen with the same name. Define an interface IBuyer which defines a method BuyFood() and an integer property Food. Implement the IBuyer interface in the Citizen and Rebel class, both Rebels and Citizens start with 0 food, when a Rebel buys food his Food increases by 5, when a Citizen buys food his Food increases by 10.
Output
The output consists of only one line on which you should print the total amount of food purchased.
Examples
Input Output
2
Stancho 27 WildMonkeys
Pesho
Gosho
Pesho
End 20
4
Stamat 23 TheSwarm
Joro 31 Terrorists
Jiraf
Jo ro
Jiraf
Joro
Stamat
Penka
End 20
Problem 8. Military Elite
Create the following class hierarchy:
• Soldier – general class for soldiers, holding id, first name and last name. o Private – lowest base soldier type, holding the field salary(decimal).
▪ LieutenantGeneral – holds a set of Privates under his command.
▪ SpecialisedSoldier – general class for all specialised soldiers – holds the corps of the soldier.
The corps can only be one of the following: Airforces or Marines.
– Engineer – holds a set of repairs. A repair holds a part name and hours worked(int).
– Commando – holds a set of missions. A mission holds code name and a state (inProgress or Finished). A mission can be finished through the method CompleteMission().
o Spy – holds the code number of the spy (int).
Extract interfaces for each class. (e.g. ISoldier, IPrivate, ILieutenantGeneral, etc.) The interfaces should hold their public properties and methods (e.g. Isoldier should hold id, first name and last name). Each class should implement its respective interface. Validate the input where necessary (corps, mission state) – input should match exactly one of the required values, otherwise it should be treated as invalid. In case of invalid corps the entire line should be skipped, in case of an invalid mission state only the mission should be skipped.
You will receive from the console an unknown amount of lines containing information about soldiers until the command “End” is received. The information will be in one of the following formats:
• Private: “Private <id> <firstName> <lastName> <salary>”
• LeutenantGeneral: “LieutenantGeneral <id> <firstName> <lastName> <salary> <private1Id> <private2Id> … <privateNId>” where privateXId will always be an Id of a private already received through the input.
• Engineer: “Engineer <id> <firstName> <lastName> <salary> <corps> <repair1Part> <repair1Hours> … <repairNPart> <repairNHours>” where repairXPart is the name of a repaired part and repairXHours the hours it took to repair it (the two parameters will always come paired).
• Commando: “Commando <id> <firstName> <lastName> <salary> <corps> <mission1CodeName> <mission1state> … <missionNCodeName> <missionNstate>” a missions cde name, description and state will always come together.
• Spy: “Spy <id> <firstName> <lastName> <codeNumber>”
Define proper constructors. Avoid code duplication through abstraction. Override ToString() in all classes to print detailed information about the object.
• Privates:
Name: <firstName> <lastName> Id: <id> Salary: <salary>
• Spy:
Name: <firstName> <lastName> Id: <id>
Code Number: <codeNumber>
• LieutenantGeneral:
Name: <firstName> <lastName> Id: <id> Salary: <salary>
Privates:
<private1 ToString()>
<private2 ToString()>
…
<privateN ToString()>
• Engineer:
Name: <firstName> <lastName> Id: <id> Salary: <salary> Corps: <corps>
Repairs:
<repair1 ToString()>
<repair2 ToString()> …
<repairN ToString()>
• Commando:
Name: <firstName> <lastName> Id: <id> Salary: <salary> Corps: <corps>
Missions:
<mission1 ToString()>
<mission2 ToString()>
…
<missionN ToString()>
• Repair:
Part Name: <partName> Hours Worked: <hoursWorked>
• Mission:
Code Name: <codeName> State: <state>
NOTE: Salary should be printed rounded to two decimal places after the separator.
Examples
Input Output
Private 1 Pesho Peshev 22.22
Commando 13 Stamat Stamov 13.1 Airforces
Private 222 Toncho Tonchev 80.08
LieutenantGeneral 3 Joro Jorev 100 222 1
End Name: Pesho Peshev Id: 1 Salary: 22.22
Name: Stamat Stamov Id: 13 Salary: 13.10
Corps: Airforces Missions:
Name: Toncho Tonchev Id: 222 Salary: 80.08
Name: Joro Jorev Id: 3 Salary: 100.00 Privates:
Name: Toncho Tonchev Id: 222 Salary: 80.08
Name: Pesho Peshev Id: 1 Salary: 22.22
Engineer 7 Pencho Penchev 12.23 Marines Boat 2 Crane 17
Commando 19 Penka Ivanova 150.15 Airforces
HairyFoot finished Freedom inProgress
End Name: Pencho Penchev Id: 7 Salary: 12.23
Corps: Marines Repairs:
Part Name: Boat Hours Worked: 2
Part Name: Crane Hours Worked: 17
Name: Penka Ivanova Id: 19 Salary: 150.15
Corps: Airforces Missions:
Code Name: Freedom State: inProgress
Problem 9. *Collection Hierarchy
Create 3 different string collections – AddCollection, AddRemoveCollection and MyList.
The AddCollection should have:
• Only a single method Add which adds an item to the end of the collection.
The AddRemoveCollection should have:
• An Add method – which adds an item to the start of the collection.
• A Remove method which removes the last item in the collection.
The MyList collection should have:
• An Add method which adds an item to the start of the collection.
• A Remove method which removes the first element in the collection.
• A Used property which displays the number of elements currently in the collection.
Create interfaces which define the collections functionality, think how to model the relations between interfaces to reuse code. Add an extra bit of functionality to the methods in the custom collections, add methods should return the index in which the item was added, remove methods should return the item that was removed.
Your task is to create a single copy of your collections, after which on the first input line you will receive a random amount of strings in a single line separated by spaces – the elements you must add to each of your collections. For each of your collections write a single line in the output that holds the results of all Add operations separated by spaces (check the examples to better understand the format). On the second input line, you will receive a single number – the amount of Remove operations you have to call on each collection. In the same manner, as with the Add operations for each collection (except the AddCollection), print a line with the results of each Remove operation separated by spaces.
Input
The input comes from the console. It will hold two lines:
• The first line will contain a random amount of strings separated by spaces – the elements you have to Add to each of your collections.
• The second line will contain a single number – the amount of Remove operations.
Output
The output will consist of 5 lines:
• The first line contains the results of all Add operations on the AddCollection separated by spaces.
• The second line contains the results of all Add operations on the AddRemoveCollection separated by spaces.
• The third line contains the result of all Add operations on the MyList collection separated by spaces.
• The fourth line contains the result of all Remove operations on the AddRemoveCollection separated by spaces.
• The fifth line contains the result of all Remove operations on the MyList collection separated by spaces.
Constraints
• All collections should have a length of 100.
• There will never be more than 100 add operations.
• The number of remove operations will never be more than the amount of add operations.
Examples
Input Output
banichka boza tutmanik
3 0 1 2
0 0 0 0 0 0 banichka boza tutmanik tutmanik boza banichka
one two three four five six seven
4 0 1 2 3 4 5 6
0 0 0 0 0 0 0 0 0 0 0 0 0 0 one two three four seven six five four
Hint
Create an interface hierarchy representing the collections. You can use a List as the underlying collection and implement the methods using the List’s Add, Remove and Insert methods.
Problem 10. *Explicit Interfaces
Create 2 interfaces IResident and IPerson. IResident should have a name, country and a method GetName().
IPerson should have a name, an age and a method GetName(). Create a class Citizen which implements both IResident and IPerson, explicitly declare that IResident’s GetName() method should return “Mr/Ms/Mrs ” before the name while IPerson’s GetName() method should return just the name. You will receive lines of citizen information from the console until the command “End” is received. Each will be in the format “<name> <country> <age>” for each line create the corresponding citizen and print his IPerson’s GetName() and his IResitent’s GetName().
Examples
Input Output
PeshoPeshev Bulgaria 20
End PeshoPeshev
Mr/Ms/Mrs PeshoPeshev
JoroJorev Bulgaria 33
EricAnderson GreatBritain 28
PeterArmstrong USA 19
End JoroJorev
Mr/Ms/Mrs JoroJorev
EricAnderson
Mr/Ms/Mrs EricAnderson
PeterArmstrong
Mr/Ms/Mrs PeterArmstrong
Hint
Check online about Explicit Interface Implementation.