Simple Recursive way of printing all the subsets of an array.

SubsetsRecursive.java

public void printAllSubsets(int[] input){

   if ((input == null) || (input.length == 0)) return;
   int N = input.length;
   int [] output = new int[N];
   printAllSubsets(input, 0, output, 0);
 }
 
 private void printAllSubsets(int [] input, int read, int [] output, int write) {
 
     if(read == input.length){
        print(write);
        return;
     }
     
     // recurse without taking the current element
     printAllSubsets(input, read+1, output, write);
   
     // recurse taking the current element
     output[write] = input[read]
     printAllSubsets(input, read+1, output, write+1);
  }

  private void print(int[] array) {
      System.out.println(Arrays.toString(array));
  }