Hackerrank Java Comparator 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 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 in java8
Approach 1.
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;
}
}
}
Approach 2.
class Checker implements Comparator {
public int compare(Object o1, Object o2) {
Player p1 = (Player) o1;
Player p2 = (Player) o2;
if (p2.score - p1.score == 0) return p1.name.compareTo(p2.name);
return p2.score - p1.score;
}
}
Approach 3.
// Write your Checker class here
class Checker implements Comparator<Player> {
@Override
public int compare(Player o1, Player o2) {
if (o1.score == o2.score) {
return o1.name.compareTo(o2.name);
}
return o2.score - o1.score;
}
}