78. Subsets

Given a set of distinct integers, nums, return all possible subsets (the power set).

Note: The solution set must not contain duplicate subsets.

Example:

Input: nums = [1,2,3]
Output:
[
  [3],
  [1],
  [2],
  [1,2,3],
  [1,3],
  [2,3],
  [1,2],
  []
]

class Solution {
    public void dfs(List<List<Integer>> ans, ArrayList<Integer>temp, int pos, int[] nums) {
        if (pos == nums.length) {
            ans.add(new ArrayList<>(temp));
            return;
        }
        
        dfs(ans, temp, pos + 1, nums);
        temp.add(nums[pos]);
        dfs(ans, temp, pos + 1, nums);
        temp.remove(temp.size() - 1);
        

    }
    public List<List<Integer>> subsets(int[] nums) {
        Arrays.sort(nums);
        List<List<Integer>> ans = new ArrayList<>();
        ArrayList<Integer> temp = new ArrayList<>();
        //ans.add(new ArrayList<>());
        dfs(ans, temp, 0, nums);
        return ans;
        
    }
}