Given a set of distinct integers, S, 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 S =[1,2,3], a solution is:[ [3], [1], [2], [1,2,3], [1,3], [2,3], [1,2], [] ]
算法思路：
题中要求求出所有的，直接暴力吧，dfs
代码如下：
1 public class Solution { List<List<Integer>> res = new ArrayList<List<Integer>>(); 2 public List<List<Integer>> subsets(int[] s) { 3 if(s == null || s.length== 0) return res; 4 Arrays.sort(s); 5 List<Integer> list = new ArrayList<Integer>(); 6 dfs(list,0,0,s); 7 return res; 8 } 9 private void dfs(List<Integer> list,int k,int count,int[] s){ 10 if(count > s.length) return; 11 if(count <= s.length){ 12 res.add(new ArrayList<Integer>(list)); 13 } 14 for(int i = k; i < s.length; i++){ 15 list.add(s[i]); 16 dfs(list,i + 1,count+1,s); 17 list.remove(list.size() - 1); 18 } 19 } 20 21 }
[leetcode]Subsets,布布扣,bubuko.com
原文：http://www.cnblogs.com/huntfor/p/3869112.html