Algorithm

Problem Name: Java Comparator

In this HackerRank Functions in Java programming problem solution,

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 2 fields: a name String and a score integer. Given an array of n Player objects, write a comparator that sorts them in order of decreasing score; if 2 r 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, n , denoting the number of players.
Each of the n subsequent lines contains a player's name and score , respectively.

Constraints

• 0 <= score <= 1000
• 2 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


Code Examples

#1 Code Example with Java Programming

Code - Java Programming


import java.util.*;

class Checker implements Comparator < Player> {
@Override
public int compare(Player p1, Player p2) {
if (p1.score == p2.score) {
return p1.name.compareTo(p2.name);
} else {
return p2.score - p1.score; // descending order
}
}
}

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);
}
}
}

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