class Solution:
  def findNumbers(self, nums):
    duplicates = []

    def swap(i, j):
      nums[i], nums[j] = nums[j], nums[i]

    for i in range(len(nums)):
      # keep swaping while item is not in position and not pointing to an index that has an item that is in position
      while nums[i] != i + 1 and nums[i] != nums[nums[i] - 1]:
        swap(i, nums[i] - 1)

    # if an item is not at the right index add it to the result
    for i in range(len(nums)):
      if nums[i] != i + 1:
        duplicates.append(nums[i])

    return duplicates