78. Subsets

Problem Link

Description

---

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.

Solution

---

Python3

class Solution:
    def subsets(self, nums: List[int]) -> List[List[int]]:
        N = len(nums)
        res = []
 
        for mask in range(1 << N):
            A = []
 
            for j in range(N):
                if mask & (1 << j):
                    A.append(nums[j])
            
            res.append(A)
        
        return res

C++

class Solution {
public:
    vector<vector<int>> subsets(vector<int>& nums) {
        int n = nums.size();
        vector<vector<int>> res;
        
        for (int i=0; i < 1<<n; ++i){
            vector<int> c;
            for (int j = 0; j < n; ++j)
                if (i >> j&1)
                    c.push_back(nums[j]);
            res.push_back(c);
        }
        
        return res;
    }
};