标签：des style blog color strong os
Given a set of distinct integers, S, return all possible subsets.
Note:
For example,
If S = [1,2,3], a solution is:
[ [3], [1], [2], [1,2,3], [1,3], [2,3], [1,2], [] ]
题解：实现一个递归的函数生成长度为level的所有子集放入结果中，然后循环的置这个level为0~S.length，即可生成所有的子集。
代码如下：
1 public class Solution { 2 public void subsetsDfs(int[] s,int level,int pos,ArrayList<Integer> result,List<List<Integer>> answer){ 3 if(result.size() == level){ 4 answer.add(new ArrayList<Integer>(result)); 5 return; 6 } 7 for(int i = pos;i < s.length;i++){ 8 result.add(s[i]); 9 subsetsDfs(s, level, i+1, result, answer); 10 result.remove(result.size()-1); 11 } 12 } 13 public List<List<Integer>> subsets(int[] S) { 14 Arrays.sort(S); 15 List<List<Integer>> answer = new ArrayList<List<Integer>>(); 16 ArrayList<Integer> result = new ArrayList<Integer>(); 17 18 for(int i = 0;i <= S.length;i++) 19 subsetsDfs(S, i, 0, result, answer); 20 return answer; 21 } 22 }
【leetcode刷题笔记】Subsets,布布扣,bubuko.com
标签：des style blog color strong os
原文地址：http://www.cnblogs.com/sunshineatnoon/p/3858209.html
