text: from typing import List
  class Solution:
      def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
          i = 0
          while i < len(nums):
              reqIndex = nums[i] - 1
              if nums[reqIndex] != nums[i]:
                  nums[i], nums[reqIndex] = nums[reqIndex], nums[i]
              else:
                  i += 1
          
          result = []
          for index, num in enumerate(nums):
              if num != index + 1:
                  result.append(index +1)
          return result
  
  
  nums = [4,3,2,7,8,2,3,1]
  ob = Solution()
  print(ob.findDisappearedNumbers(nums))