169. Majority Element (solution 2)

package LeetCode_169

/**
 * 169. Majority Element
 * https://leetcode.com/problems/majority-element/
 * Given an array of size n, find the majority element.
 * The majority element is the element that appears more than ? n/2 ? times.
You may assume that the array is non-empty and the majority element always exist in the array.
Example 1:
Input: [3,2,3]
Output: 3

Example 2:
Input: [2,2,1,1,1,2,2]
Output: 2
 * */
class Solution {
    /*
    * solution 1: HashMap, Time:O(n), Space:O(n);
    * solution 2: Moore Vote, Time:O(n), Space:O(1),
    * */
    fun majorityElement(nums: IntArray): Int {
       /*
        solution 2:
        https://www.cs.utexas.edu/~moore/best-ideas/mjrty/index.html,
        https://www.cnblogs.com/grandyang/p/4233501.html;
         */
        var result = 0
        var count = 0
        for (num in nums) {
            if (count == 0) {
                result = num
                count++
            } else if (num == result) {
                count++
            } else {
                count--
            }
        }
        return result
    }
}