leetcode------Subsets II
标题: | Subsets II |
通过率: | 27.5 |
难度: | 中等 |
Given a collection of integers that might contain duplicates, 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 = [1,2,2]
, a solution is:
[ [2], [1], [1,2,2], [2,2], [1,2], [] ]
从第一个版本中可以看出来,这里需要增加相同判断。具体看代码
1 public class Solution { 2 public ArrayList<ArrayList<Integer>> subsetsWithDup(int[] num) { 3 ArrayList<ArrayList<Integer>> res=new ArrayList<ArrayList<Integer>>(); 4 ArrayList<Integer> tmp=new ArrayList<Integer>(); 5 Arrays.sort(num); 6 dfs(res,tmp,0,num); 7 return res; 8 } 9 public void dfs(ArrayList<ArrayList<Integer>> res,ArrayList<Integer> tmp,int start,int[] num){ 10 if(!res.contains(tmp)) 11 res.add(new ArrayList<Integer>(tmp)); 12 for(int i=start;i<num.length;i++){ 13 tmp.add(num[i]); 14 dfs(res,tmp,i+1,num); 15 tmp.remove(tmp.size()-1); 16 } 17 } 18 }