Day_15.java

// Subsets II
class Solution {
    public void func(int i,int n,int[] nums,List<Integer> list,List<List<Integer>> ans){
        if(i == n){
            ans.add(new ArrayList<>(list));
            return;
        }
        list.add(nums[i]);
        func(i+1,n,nums,list,ans);
        list.remove(list.size()-1);
        for(int idx = i+1;idx<n;idx++){
            if(nums[i] != nums[idx]){
                func(idx,n,nums,list,ans);
                return;
            }
        }
        func(n,n,nums,list,ans);
    }

    public List<List<Integer>> subsetsWithDup(int[] nums) {
        int n = nums.length;
        Arrays.sort(nums);
        List<List<Integer>> ans = new ArrayList<>();
        List<Integer> list = new ArrayList<>();
        func(0,n,nums,list,ans);
        return ans;
    }
}