Generate Powersets Java

import java.util.ArrayList;
import java.util.Scanner;

//Zachary Collins
//100% Vegetarian Code

public class One {
	
	//The main class
	public static void main(String[] args) {
		//Collect user input for n 
		int n = input();
		ArrayList<Integer> list = count(n);
		generateSubsets(list);
	}
	
	/**
	 *  Given an n, returns an array list containing each number as an element up to n
	 *  @param  int n 
	 *  @return ArrayList arr 
	 * 
	 */
	private static ArrayList<Integer> count(int n) {
		ArrayList<Integer> list = new ArrayList<Integer>();
		for (int i = 1; i<=n; i++) {
			list.add(i);
		}
		return list;
	}
	
	/**
	 *  Generate and print all subsets possible given an integer 
	 *  @param an integer list containing teh numbers up to the given n input
	 * 
	 */
	private static void generateSubsets(ArrayList<Integer> list)
	{
		  //Start keeping track of how long the algorithm takes
		  long startTime = System.currentTimeMillis();
				
		  ArrayList<Integer> retList = new ArrayList<Integer>();
		  
		  //<< shifts to left >> shifts to right
		  int subsets = 1 << list.size(); 
	
		  for(int i = 0; i < subsets; i++) {
		    int pos = list.size() - 1;
		    int mask = i;
			   
		    while(mask > 0) {
		    	if((mask & 1) == 1)
		    		retList.add(list.get(pos));
		    		//n two to the right
		    		mask >>= 1;
		    		pos--;
		    }
		    
		    //replace the [ , ] in the arraylist with set notation, print
		    System.out.println(retList.toString()
		    		.replace('[', '{')
		    		.replace(']', '}')
		    );
		  //clear list in prep for more additions
    		  retList.clear();
		  }
          	  //Print out the elapsed time of the algorithm
		  long stopTime = System.currentTimeMillis();
		  long elapsedTime = stopTime - startTime;
		  System.out.println("Runtime: " + elapsedTime + " ms");
	}
	
	/**
	 *  Collect user input for n
	 *  @return int n 
	 * 
	 */
	private static int input()	{
		Scanner input = new Scanner(System.in);
		System.out.println("Enter a value for n ");
		return input.nextInt();
	}
}