HackerRank Covariant Return Types solution in Java

HackerRank Covariant Return Types solution in Java – In this HackerRank Java Covariant Return Types problem in the Java programming language, Java allows for Covariant Return Types, which means you can vary your return type as long you are returning a subclass of your specified return type.

You will be given a partially completed code in the editor where the main method takes the name of a state (i.e., WestBengal, or AndhraPradesh) and prints the national flower of that state using the classes and methods written by you.

HackerRank Covariant Return Types problem solution in java programming.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

//Complete the classes below
class Flower {
    String whatsYourName() {
        return "I have many names and types.";
    }
}

class Jasmine extends Flower {
    @Override
    String whatsYourName() {
        return "Jasmine";
    }
}

class Lily extends Flower {
    @Override
    String whatsYourName() {
        return "Lily";
    }
}

class Lotus extends Flower {
    @Override
    String whatsYourName() {
        return "Lotus";
    }
}

class Region {
    Flower yourNationalFlower() {
        return new Flower();
    }
}

class WestBengal extends Region {
    @Override
    Jasmine yourNationalFlower() {
        return new Jasmine();
    }
}

class Karnataka extends Region {
    @Override
    Lotus yourNationalFlower() {
        return new Lotus();
    }
}

class AndhraPradesh extends Region {
    @Override
    Lily yourNationalFlower() {
        return new Lily();
    }
}


public class Solution {
  public static void main(String[] args) throws IOException {
      BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
      String s = reader.readLine().trim();
      Region region = null;
      switch (s) {
        case "WestBengal":
          region = new WestBengal();
          break;
        case "AndhraPradesh":
          region = new AndhraPradesh();
          break;
      }
      Flower flower = region.yourNationalFlower();
      System.out.println(flower.whatsYourName());
    }
}

Second solution in java8 programming.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

//Complete the classes below
class Flower {
    String whatsYourName() {
        return "I have many names and types.";
    }
}

class Jasmine extends Flower {
    @Override
    String whatsYourName() {
        return "Jasmine";
    }
}

class Lily extends Flower {
    @Override
    String whatsYourName() {
        return "Lily";
    }
}

class Lotus extends Flower {
    @Override
    String whatsYourName() {
        return "Lotus";
    }
}

class Region {
    Flower yourNationalFlower() {
        return new Flower();
    }
}

class WestBengal extends Region {
    @Override
    Jasmine yourNationalFlower() {
        return new Jasmine();
    }
}

class Karnataka extends Region {
    @Override
    Lotus yourNationalFlower() {
        return new Lotus();
    }
}

class AndhraPradesh extends Region {
    @Override
    Lily yourNationalFlower() {
        return new Lily();
    }
}


public class Solution {
  public static void main(String[] args) throws IOException {
      BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
      String s = reader.readLine().trim();
      Region region = null;
      switch (s) {
        case "WestBengal":
          region = new WestBengal();
          break;
        case "AndhraPradesh":
          region = new AndhraPradesh();
          break;
      }
      Flower flower = region.yourNationalFlower();
      System.out.println(flower.whatsYourName());
    }
}