SubsetsII（containsduplicates）

Given a collection of integers that might contain duplicates, nums, return all possible subsets.

Note: The solution set must not contain duplicate subsets.

For example,
If nums &＃61; [1,2,2], a solution is:

[[2],[1],[1,2,2],[2,2],[1,2],[]
] 代码如下&＃xff1a;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;public class SubsetsIIContainsDuplicates {public List> subsetsII(int[] nums){List> list &＃61; new ArrayList<>();Arrays.sort(nums);backtrack(list,new ArrayList<>(),nums,0);return list;}private void backtrack(List> list, ArrayList arrayList, int[] nums, int start) {list.add(new ArrayList<>(arrayList));for(int i&＃61;start; istart && nums[i]&＃61;&＃61;nums[i-1]) //防止重复的组合出现continue;arrayList.add(nums[i]);backtrack(list,arrayList,nums,i&＃43;1);arrayList.remove(arrayList.size()-1);}}}