LeetCode No.78 Subsets

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

Note: 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],  []]

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题目链接：https://leetcode.com/problems/subsets/

题目大意：求出给定集合的所有子集。

思路：深搜（dfs）或宽搜（bfs）。

参考代码：

class Solution {public:    vector<vector<int>> subsets(vector<int>& nums) {        int n = nums.size() ;        sort ( nums.begin() , nums.end() ) ;        vector <int> temp ;        vector < vector <int> > ans ( 1 , temp ) ;        queue < vector <int> > q ;        q.push ( temp ) ;        while ( ! q.empty() )        {            temp = q.front() ;            q.pop() ;            for ( int i = 0 ; i < n ; i ++ )            {                if ( temp.empty() || nums[i] > temp.back() )                {                    vector <int> tt = temp ;                    tt.push_back ( nums[i] ) ;                    ans.push_back ( tt ) ;                    q.push ( tt ) ;                }            }        }        return ans ;    }};