Java Comparator HackerRank Solution

Problem:-

Comparators are used to compare two objects. In this challenge, you'll create a comparator and use it to sort an array.

The Player class is provided for you in your editor. It has  fields: a  String and a  integer.

Given an array of  Player objects, write a comparator that sorts them in order of decreasing score; if  or more players have the same score, sort those players alphabetically by name. To do this, you must create a Checker class that implements the Comparator interface, then write an int compare(Player a, Player b) method implementing the Comparator.compare(T o1, T o2)method.

Input Format

Input from stdin is handled by the locked stub code in the Solution class.

The first line contains an integer, , denoting the number of players. 
Each of the  subsequent lines contains a player's  and , respectively.

Constraints

•  players can have the same name.
• Player names consist of lowercase English letters.

Output Format

You are not responsible for printing any output to stdout. The locked stub code in Solution will create a Checker object, use it to sort the Player array, and print each sorted element.

Sample Input

5
amy 100
david 100
heraldo 50
aakansha 75
aleksa 150

Sample Output

aleksa 150
amy 100
david 100
aakansha 75
heraldo 50

Solution:-

import java.util.*;

class Checker implements Comparator<Player>{

@Override

public int compare(Player a, Player b){

if (a.score == b.score){

return a.name.compareTo(b.name);//alphabetically

} else {

return b.score - a.score;//decreasing

}

}

}

class Player{

String name;

int score;

Player(String name, int score){

this.name = name;

this.score = score;

}

}

class Solution {

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

int n = scan.nextInt();

Player[] player = new Player[n];

Checker checker = new Checker();

for(int i = 0; i < n; i++){

player[i] = new Player(scan.next(), scan.nextInt());

}

scan.close();

Arrays.sort(player, checker);

for(int i = 0; i < player.length; i++){

System.out.printf("%s %s\n", player[i].name, player[i].score);

}

}

}