#90 - Subsets II

Medium • View on LeetCode • View on GitHub

Problem Description

Given an integer array nums that may contain duplicates, return all possible subsets (the power set).

The solution set must not contain duplicate subsets. Return the solution in any order.

Solution

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var subsetsWithDup = function(nums) {
  const seen = new Set();
  const result = [];
  dfs([], 0);

  function dfs(subset, start) {
    const key = subset.sort((a, b) => a - b).join('');
    if (!seen.has(key)) {
      result.push(subset);
      seen.add(key);
    }
    for (let index = start; index < nums.length; index++) {
      dfs([...subset, nums[index]], index + 1);
    }
  }

  return result;
};