Problem

Given a set of distinct integers, return all possible subsets.
Input: [1,2,3]
Output:
[
  [3],
  [1],
  [2],
  [1,2,3],
  [1,3],
  [2,3],
  [1,2],
  []
]

Solution

# Solution:
# The solution is to use a recursive function that takes in the input array and the current subset.
# The function will iterate through the input array and add each element to the current subset.
# It will then call itself with the input array and the new subset.
# The function will also call itself with the input array and the current subset.
# This will allow the function to create all possible subsets.
# The function will return a list of all possible subsets.
# The function will also add the empty set to the list of subsets.
# The solution is optimal because it will create all possible subsets.

def subsets(nums):
    """
    :type nums: List[int]
    :rtype: List[List[int]]
    """
    def helper(nums, subset):
        subsets = []
        for i in range(len(nums)):
            new_subset = subset + [nums[i]]
            subsets.append(new_subset)
            subsets += helper(nums[i+1:], new_subset) return subsets
    return helper(nums, []) + [[]]

print(subsets([1,2,3]))