Majority Element II

Question

Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times. The algorithm should run in linear time and in O(1) space.

Code

class Solution(object):
    def majorityElement(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """
        if nums == []:
            return []
        candidate1, candidate2, count1, count2 = 0, 1, 0, 0
        for num in nums:
            if num == candidate1:
                count1 += 1
            elif num == candidate2:
                count2 += 1
            elif count1 == 0:
                candidate1 = num
                count1 = 1
            elif count2 == 0:
                candidate2 = num
                count2 = 1
            else:
                count1 -= 1
                count2 -= 1
        return [num for num in set([candidate1, candidate2]) if nums.count(num) > len(nums) // 3]