Java Singleton Pattern Hackerrank Solution For Explanation Watch Video: Sample Input hello world Sample Output Hello I am a singleton! Let me say hello world to you Code: import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*; import java.lang.reflect.*; class Singleton{ public String str; private Singleton(){ } public static Singleton getSingleInstance(){ return new Singleton(); } }