#include "s0090_subsets_ii.hpp"

void subsetsWithDupDFS(vector<int> &subset, vector<vector<int>> &result,
                       vector<int> &nums, int startIndex, vector<bool> &used) {
  int size = nums.size();
  // 结束条件
  if (startIndex == size) return;

  for (int i = startIndex; i < size; ++i) {
    // 剪枝，保留树枝重复
    if (i > 0 && nums[i] == nums[i - 1] && used[i - 1] == false) continue;
    subset.push_back(nums[i]);
    result.push_back(subset);
    used[i] = true;
    subsetsWithDupDFS(subset, result, nums, i + 1, used);
    used[i] = false;
    subset.pop_back();
  }
}

vector<vector<int>> S0090::subsetsWithDup(vector<int> &nums) {
  vector<int> subset{};
  vector<vector<int>> result{};
  vector<bool> used(nums.size(), false);
  sort(nums.begin(), nums.end());
  subsetsWithDupDFS(subset, result, nums, 0, used);
  result.push_back(vector<int>{});
  return result;
}