package Array;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Iterator;

public class Subsets

{

public ArrayList<ArrayList<Integer>> subsets(int s[])

{

Arrays.sort(s);

ArrayList<ArrayList<Integer>> result = new ArrayList<ArrayList<Integer>>();

ArrayList<Integer> path = new ArrayList<Integer>();

subsets(s,path, 0, result);

return result;

}

public void subsets(int s[], ArrayList<Integer> path, int index ,ArrayList<ArrayList<Integer>> result)

{

@SuppressWarnings("unchecked")

ArrayList<Integer> array = (ArrayList<Integer>) path.clone();

result.add(array);

for (int i = index; i < s.length; i++) {

path.add(s[i]);

subsets(s, path, i+1, result);

path.remove(path.size()-1);

}

// if(s.length == index)

// {

// @SuppressWarnings("unchecked")

// ArrayList<Integer> array = (ArrayList<Integer>) path.clone();

// result.add(array);

// return;

// }

// //不选择当前数

// subsets(s, path, index+1, result);

// //选择当前数

// path.add(s[index]);

// subsets(s, path, index+1, result);

// path.remove(path.size()-1);

}

public static void main(String[] args)

{

Subsets set = new Subsets();

int s[] = {4,1,0};

ArrayList<ArrayList<Integer>> result = set.subsets(s);

for (Iterator<ArrayList<Integer>> iterator = result.iterator(); iterator.hasNext();)

{

ArrayList<Integer> arrayList = (ArrayList<Integer>) iterator.next();

System.out.println(arrayList);

}

}

}