Difficulty:: Medium
Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set).
Note: The solution set must not contain duplicate subsets.
Example:
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| Input: [1,2,2]
Output:
[
[2],
[1],
[1,2,2],
[2,2],
[1,2],
[]
]
|
Solution
Language: Java
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| class Solution {
public List<List<Integer>> subsetsWithDup(int[] nums) {
List<List<Integer>> result = new ArrayList<>();
if (nums == null) {
return result;
}
Arrays.sort(nums);
dfsHelper(nums, result, new ArrayList<Integer>(), 0);
return result;
}
private void dfsHelper(int[] nums, List<List<Integer>> result, List<Integer> subset, int index) {
result.add(new ArrayList<Integer>(subset));
for (int i = index; i < nums.length; i++) {
if (i != index && nums[i] == nums[i - 1]) {
continue;
}
subset.add(nums[i]);
dfsHelper(nums, result, subset, i + 1);
subset.remove(subset.size() - 1);
}
}
}
|