LeetCode78. Subsets

• 求一个序列的子集

• 位运算

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