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90. Subsets II

MediumOpen on LeetCodeProblem statement

Problem Statement

90. Subsets II

Medium


Given an integer array nums that may contain duplicates, return all possible subsets (the power set).

The solution set must not contain duplicate subsets. Return the solution in any order.

 

Example 1:

Input: nums = [1,2,2]
Output: [[],[1],[1,2],[1,2,2],[2],[2,2]]

Example 2:

Input: nums = [0]
Output: [[],[0]]

 

Constraints:

Java

Source file
class Solution {

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

    void solve(int[] nums, List<List<Integer>> ans, List<Integer> curr, int idx) {
        ans.add(new ArrayList<>(curr));
        for (int i = idx; i < nums.length; i++) {
            if (i > idx && nums[i] == nums[i - 1])
                continue;
            curr.add(nums[i]);
            solve(nums, ans, curr, i + 1);
            curr.remove(curr.size() - 1);
        }
    }
}