Subsets.js

/*
Subsets 
https://leetcode.com/problems/subsets/description/

Given a set of distinct integers, nums, return all possible subsets (the power set).

Note: The solution set must not contain duplicate subsets.

Example:

Input: nums = [1,2,3]
Output:
[
  [3],
  [1],
  [2],
  [1,2,3],
  [1,3],
  [2,3],
  [1,2],
  []
]
*/

var subsets = function (nums) {
  var subsetByPosition = function (nums, position, current) {
    if (position == nums.length) {
      return [current];
    }
    var currentRight = current.slice().concat([nums[position]]);
    return subsetByPosition(nums, position + 1, currentRight).concat(
      subsetByPosition(nums, position + 1, current)
    );
  };

  return subsetByPosition(nums, 0, []);
};

module.exports.subsets = subsets;