Hello coders, today we are going to solve Day 13: Abstract Classes HackerRank Solution in C++, Java and Python.
Objective
Today, we will extend what we learned yesterday about Inheritance to Abstract Classes. Because this is a very specific object oriented concept, submissions are limited to the few languages that use this construct.
Task
Given a Book class and a Solution class, write a MyBook class that does the following:
- Inherits from Book
- Has a parameterized constructor taking these 3 parameters:
- string title
- string author
- int price
- Implements the Book class’ abstract display() method so it prints these lines:
- Title: , a space, and then the current instance’s title.
- Author:, a space, and then the current instance’s author.
- Price:, a space, and then the current instance’s price.
Note: Because these classes are being written in the same file, you must not use an access modifier (e.g.:public ) when declaring MyBook or your code will not execute.
Input Format
You are not responsible for reading any input from stdin. The Solution class creates a Book object and calls the MyBook class constructor (passing it the necessary arguments). It then calls the display method on the Book object.
Output Format
The void display() method should print and label the respective title, author, and price of the MyBook object’s instance (with each value on its own line) like so:
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Title: $title Author: $author Price: $price |
Note: The $ is prepended to variable names to indicate they are placeholders for variables.
Sample Input
The following input from stdin is handled by the locked stub code in your editor:
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The Alchemist Paulo Coelho 248 |
Sample Output
The following output is printed by your display() method:
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Title: The Alchemist Author: Paulo Coelho Price: 248 |
Solution – Day 13: Abstract Classes
C++
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#include <cmath> #include <cstdio> #include <vector> #include <iostream> #include <algorithm> #include <string> using namespace std; class Book{ protected: string title; string author; public: Book(string t,string a){ title=t; author=a; } virtual void display()=0; }; class MyBook : Book{ private: int price; public: MyBook(string t,string a,int price):Book(t,a){ this->price = price; } void display(){ cout << "Title: " << title << endl << "Author: " << author << endl << "Price: " << price << endl; } }; int main() { string title,author; int price; getline(cin,title); getline(cin,author); cin>>price; MyBook novel(title,author,price); novel.display(); return 0; } |
Java
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import java.util.*; abstract class Book { String title; String author; Book(String title, String author) { this.title = title; this.author = author; } abstract void display(); } class MyBook extends Book{ int price; MyBook(String title,String author,int price ){ super(title,author); this.price=price; } void display() { System.out.println("Title: "+title); System.out.println("Author: "+author); System.out.println("Price: "+price); } } public class Solution { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String title = scanner.nextLine(); String author = scanner.nextLine(); int price = scanner.nextInt(); scanner.close(); Book book = new MyBook(title, author, price); book.display(); } } |
Python
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import java.util.*; abstract class Book { String title; String author; Book(String title, String author) { this.title = title; this.author = author; } abstract void display(); } class MyBook extends Book{ int price; MyBook(String title,String author,int price ){ super(title,author); this.price=price; } void display() { System.out.println("Title: "+title); System.out.println("Author: "+author); System.out.println("Price: "+price); } } public class Solution { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String title = scanner.nextLine(); String author = scanner.nextLine(); int price = scanner.nextInt(); scanner.close(); Book book = new MyBook(title, author, price); book.display(); } } |
Disclaimer: The above Problem (Day 13: Abstract Classes) is generated by Hacker Rank but the Solution is Provided by LearnKro. This tutorial is only for Educational and Learning Purpose.
