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],
[]
]