Majority Element II

题目
Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times.

答案

class Solution {
    public List<Integer> majorityElement(int[] nums) {
        List<Integer> list = new ArrayList<>();
        
        int candidate1 = 0, candidate2 = 1, count1 = 0, count2 = 0;
        for(int x : nums) {
            if(x == candidate1) 
                count1++;
            else if(x == candidate2)
                count2++;
            else if(count1 == 0) {
                candidate1 = x;
                count1 = 1;                
            }
            else if(count2 == 0) {
                candidate2 = x;
                count2 = 1;                
            }
            else {
                count1--;
                count2--;
            }
        }
        
        count1 = 0;
        count2 = 0;
        for(int x : nums) {
            if(x == candidate1) count1++;
            if(x == candidate2) count2++;
        }
        if(count1 > nums.length / 3) list.add(candidate1);
        if(count2 > nums.length / 3) list.add(candidate2);
        return list;
    }
}