PR1.java

/****************************************************************************
 * Code to print all subsets of a string with recursion

*******************************************************************************/
import java.util.*; 
public class Main
{
	public static void main(String[] args) {
	   subseq("","abc");
	}
	
	static void subseq(String p,String up)
	{
	    if(up.isEmpty()){
	        System.out.println(p);
	        return;
	    } 
	    
	    char ch = up.charAt(0);
	    
	    subseq(p+ch,up.substring(1));
	    subseq(p,up.substring(1));
	}


	static ArrayList<String>   Subseq(String p,String up)
	{
	    if(up.isEmpty()){
	        ArrayList<String> list = new ArrayList<>();
	        list.add(p);
	        return list;
	    }
	    
	    char ch = up.charAt(0);
	    
	    ArrayList<String> left = Subseq(p+ch,up.substring(1));
	    ArrayList<String> right = Subseq(p,up.substring(1));
	    left.addAll(right);
	    return left;
	}
}