Clean Code-style refactor of Majority Element solution

MajorityElementClean.kt

class Solution {

    private var count = 0
    private var candidate: Int? = null

    fun majorityElement(nums: IntArray): Int {
        for (num in nums) {
            candidate = updateCandidateForZeroCount(num)
            count = updateCountForCandidate(num)
        }

        return candidate!!
    }

    private fun updateCandidateForZeroCount(num: Int): Int? {
        if (count == 0) {
            return num
        }
        return candidate
    }

    private fun updateCountForCandidate(num: Int): Int {
        return if (num == candidate) {
            count + 1
        } else {
            count - 1
        }
    }
}