https://www.hackerrank.com/challenges/game-of-thrones

gameOfThrones.java

import java.util.Collections;
import java.util.Scanner;
import java.util.ArrayList;
public class gameOfThrones {

	public static void main(String[] args) {
		
		Scanner sc=new Scanner(System.in);
		String s=sc.next();
		
		ArrayList<Character> arr=new ArrayList<Character>();
		ArrayList<Character> t=new ArrayList<Character>();
		
		for(int i=0;i<s.length();++i){
			char ch=s.charAt(i);
			arr.add(ch);
			if(!t.contains(ch)){
				t.add(ch);
			}
		}
		
		boolean flag=true;
		
		for(int i=0;i<t.size();++i){
			int x=Collections.frequency(arr, t.get(i));
			if(x%2!=0){
				if(s.length()%2!=0 && flag==true){
					flag=false;
				}
				else{
					System.out.println("NO");
					System.exit(0);
				}
			}
		}
		
		System.out.println("YES");
	}
}