Question Definition
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.
For example,
If nums = [1,2,2], a solution is:
[
[2],
[1],
[1,2,2],
[2,2],
[1,2],
[]
]
Java Solution
class Solution {
List<List<Integer>> list;
List<Integer> al;
public List<List<Integer>> subsetsWithDup(int[] nums) {
list = new ArrayList<List<Integer>>();
al = new ArrayList<Integer>();
Arrays.sort(nums);
count(nums,al,0);
return list;
}
private void count(int[] nums,List<Integer> al,int j){
list.add(new ArrayList<Integer>(al));
for(int i = j; i < nums.length;i++){
if(i == j || nums[i] != nums[i-1]){
al.add(nums[i]);
count(nums,al,i+1);
al.remove(al.size()-1);
}
}
}
}
Comments