subsets.java

import java.util.*;  
public class GenerateSubsets {

	/*

	 * Given a input array of size n elements find all the subsets.

	 */

    public static String getString(char[] subset, int subStIndex){
        String res = "";
        int i = 0;
        while(i < subStIndex)
        {
            res += subset[i];
            i += 1;
        }
        
        return res;
    }
	public static void generateSubsets(char[] arr, int start, char[] subset, Set <String> result, int subStIndex) {

		
		
		if (start == arr.length) {
		    System.out.print(start); System.out.print(" "); System.out.print(subStIndex); System.out.print(" ");

			System.out.println("Value of subset :" + new String(subset));

			result.add(getString(subset, subStIndex));

			return;

		} else {

			generateSubsets(arr, start+1, subset, result, subStIndex);

			subset[subStIndex] = arr[start];

			//System.out.println("Value of subset in recursion:" + new String(subset));

			generateSubsets(arr, start+1, subset, result, subStIndex+1);

			return;

		}

	}

	

	public static void main(String [] args) {

		char[] arr = {'a','b','c'};

		 Set <String> result = new LinkedHashSet<>();

		char [] subset = new char[arr.length];

		generateSubsets(arr,  0, subset, result, 0);

		for(String c :result) {

			System.out.println("The subsets are: " + c);

		}

	}
}