78.Subsets

題目：
https://leetcode.com/problems/subsets/

難度 : Medium

Python代碼

class Solution(object):
    def subsets(self, nums):
        """
        :type nums: List[int]
        :rtype: List[List[int]]
        """
        results = [[]]
        for num in nums:
            results.extend([result + [num] for result in results])
        return results
            

可是我不能理解，為嘛我寫的這個(gè)不work.

??

def subsets(nums):
    """
    :type nums: List[int]
    :rtype: List[List[int]]
    """
    results = [[]]
    for num in nums:
        for result in results:
            results.extend([result + [num]])
    return results