78. Subsets

Medium (Trung bình) Python 🔗 Xem trên LeetCode

📋 Đề Bài

Given an integer array nums of unique elements, return all possible subsets (the power set).

The solution set must not contain duplicate subsets. Return the solution in any order.

 

Example 1:

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

Example 2:

Input: nums = [0]
Output: [[],[0]]

 

Constraints:

  • 1 <= nums.length <= 10
  • -10 <= nums[i] <= 10
  • All the numbers of nums are unique.

🧠 Thuật Toán & Kỹ Thuật

Bit Manipulation (Thao tác bit)
⏱️ Thời gian O(n²)
💾 Không gian O(n)

💻 Lời Giải

Python 0078-subsets.py 
class Solution:
    def subsets(self, nums: List[int]) -> List[List[int]]:
        ans = []
        n = len(nums)
        
        for mask in range(1 << n):
            tmp = []
            
            for i in range(n):
                if not (mask >> i) & 1:
                    continue    
                tmp += [nums[i]]
            
            ans += [tmp]
        
        return ans