90. Subsets II

Problem

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:

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

Solution

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var subsetsWithDup = function(nums) {
  var res = [];
  nums.sort((a, b) => a - b);
  helper(nums, 0, res, []);
  return res;
};

var helper = function (nums, start, res, now) {
  res.push(Array.from(now));

  for (var i = start; i < nums.length; i++) {
    if (i === start || nums[i] !== nums[i - 1]) {
      now.push(nums[i]);
      helper(nums, i + 1, res, now);
      now.pop();
    }
  }
};

Explain:

nope.

Complexity:

• Time complexity :
• Space complexity :