78. Subsets

Difficulty:
Medium
Related Topics:
Similar Questions:

Problem

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],
  []
]

Solution (Java)

class Solution {
    public List<List<Integer>> subsets(int[] nums) {
        List<List<Integer>> res = new ArrayList<>();
        solve(nums, new ArrayList<>(), res, 0);
        return res;
    }

    private void solve(int[] nums, List<Integer> temp, List<List<Integer>> res, int start) {
        res.add(new ArrayList<>(temp));
        for (int i = start; i < nums.length; i++) {
            temp.add(nums[i]);
            solve(nums, temp, res, i + 1);
            temp.remove(temp.size() - 1);
        }
    }
}

Solution (Javascript)

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var subsets = function(nums) {
  var res = [];
  helper(nums, res, [], 0);
  return res;
};

var helper = function (nums, res, arr, start) {
  var len = nums.length;

  res.push(Array.from(arr));

  if (start === len) return;

  for (var i = start; i < len; i++) {
    arr.push(nums[i]);
    helper(nums, res, arr, i + 1);
    arr.pop();
  }
};

Explain:

nope.

Complexity: