Leetcode No.78 Subsets

Question：

Given a set of distinct integers, nums, return all possible subsets.

Note:

• Elements in a subset must be in non-descending order.
• 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],  []]

Solution:先插入一个空的vector<int>，然后遍历给每个一插入的vector<int>加入一个新的数字

C++ Codes：

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