<filename>find-all-numbers-disappeared-in-an-array/find-all-numbers-disappeared-in-an-array.py
class Solution:
    def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
        l=[]
        sett = set(nums)
        for i in range(1,len(nums)+1):
            if i not in sett:
                l.append(i)

        return l
<filename>find-all-numbers-disappeared-in-an-array/find-all-numbers-disappeared-in-an-array.py
class Solution:
    def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
        l=[]
        sett = set(nums)
        for i in range(1,len(nums)+1):
            if i not in sett:
                l.append(i)

        return l