Subsets

想说的是，自己在写code的时候，请能够清楚，写的每一点代码都在代表什么，想要怎样的结果，能不能不要不过脑子的写code，能不能对每点code负责啊。

看看咋错的。

这个遵循模板。

public class Solution {    public List<List<Integer>> subsets(int[] nums) {        List<List<Integer>> results = new LinkedList<>();        if (nums == null || nums.length == 0) {            return results;        }        List<Integer> list = new LinkedList<>();        subsetsHelper(results, list, nums, 0);        return results;    }        private void subsetsHelper(List<List<Integer>> results, List<Integer> list, int[] nums, int pos){        //if (pos == nums.length) {            results.add(new LinkedList<>(list));        //    return;        //}        for (int i = pos; i < nums.length; i++) {            list.add(nums[i]);            subsetsHelper(results, list, nums, i + 1);            list.remove(list.size() - 1);        }    }}

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:

[  [3],  [1],  [2],  [1,2,3],  [1,3],  [2,3],  [1,2],  []]