import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
public class SubsetsII {
public List> subsetsWithDup(int[] nums) {
List> result = new LinkedList>();
if (nums.length == 0) {
return result;
}
/**
* 千万别掉了排序
*/
Arrays.sort(nums);
subsetsWithDup(nums, 0, result, new LinkedList());
return result;
}
private void subsetsWithDup(int[] nums, int start, List> list, List path) {
if (start == nums.length) {
list.add(new LinkedList(path));
return;
}
path.add(nums[start]);
subsetsWithDup(nums, start + 1, list, path);
path.remove(path.size() - 1);
// 既然不带当前字符，那后面如果重复的都别带，否则就是带了当前字符的子集
for ( ; start + 1 < nums.length && nums[start + 1] == nums[start]; start++);
subsetsWithDup(nums, start + 1, list, path);
}
}