Leetcode — 448

448. Find All Numbers Disappeared in an Array

class Solution:
    def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
        for n in nums:
            i = abs(n) - 1
            nums[i] = abs(nums[i])*-1
        res = []
        for i, v in enumerate(nums):
            if v > 0:
                res.append(i+1)
        return res