Find All Numbers Disappeared in an Array

class Solution(object):
    def findDisappearedNumbers(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """
        for i in nums:
            idx = abs(i)-1
            nums[idx] = -1 * abs(nums[idx])

        return [i for i, e in enumerate(nums, 1) if e > 0]