Subsets II

Description

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(javascript)

// 关键是如何去重或者避免重复
const subsetsWithDup = (nums = []) => {
  const result = []
  nums.sort((a, b) => a - b)

  const aux = (index, current) => {
    result.push(current)
    for (let i = index; i < nums.length; i++) {
      if (i > index && nums[i] === nums[i - 1]) {
        continue
      }
      aux(i + 1, [...current, nums[i]])
    }
  }
  aux(0, [])
  return result
}