Subsets (easy)

Problem Statement

Given a set with distinct elements, find all of its distinct subsets.

Example 1:

Input: [1, 3]
Output: [], [1], [3], [1,3]

Example 2:

Input: [1, 5, 3]
Output: [], [1], [5], [3], [1,5], [1,3], [5,3], [1,5,3]

Constraints:

1 <= nums.length <= 10
-10 <= nums[i] <= 10
All the numbers of nums are unique.

Try it yourself

Try solving this question here:

.....

Like the course? Get enrolled and start learning!

Trang Luong

· a year ago

class Solution:
  # cascading, at each step, add the number to all current subsets
  # If it's a list of list, make sure copy each time or else it will modify reference
  # def find_subsets(self, nums):
  #   subsets = [[]]
  #   #[1, 2, 3]
  #   for num in nums: 
  #     subsets_copy = subsets.copy() # O(n)
  #     for subset in subsets_copy: # O(2^n) (k start with 1 and grow until 2^n for n)
  #       new_subnet = subset.copy() # O(N)
  #       new_subnet.append(num)
  #       subsets.append(new_subnet)
  #   return subsets

  def find_subsets(self, nums):
    result_subsets = []
    self.backtrack(0, [], result_subsets, nums)
    return result_subsets
  # Backtracking solution, building each solution as we go down a tree of decision to build subset
  # backtrack(0, [], [],