Subsets

Given a set of distinct integers, nums, return all possible subsets.

Note: The solution set must not contain duplicate subsets.

For example,

If nums = [1,2,3], a solution is:

  1. [
  2.   [3],
  3.   [1],
  4.   [2],
  5.   [1,2,3],
  6.   [1,3],
  7.   [2,3],
  8.   [1,2],
  9.   []
  10. ]

Solution:

  1. public class Solution {
  2.   public List<List<Integer>> subsets(int[] nums) {
  3.     List<List<Integer>> res = new ArrayList<List<Integer>>();
  4.     res.add(new ArrayList<Integer>());
  6.     Arrays.sort(nums);
  8.     for (int i = 0; i < nums.length; i++) {
  9.       int size = res.size();
  11.       for (int j = 0; j < size; j++) {
  12.         List<Integer> sol = new ArrayList<Integer>(res.get(j));
  13.         sol.add(nums[i]);
  14.         res.add(sol);
  15.       }
  16.     }
  18.     return res;
  19.   }
  20. }