Majority Element II

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.

Solution:

public class Solution {
    public List<Integer> majorityElement(int[] nums) {
        int num1=0, num2=1, count1=0, count2=0;
        for(int i=0; i<nums.length; i++){
            if(nums[i]==num1)
                count1++;
            else if(nums[i]==num2)
                count2++;
            else if(count1==0){
                num1 = nums[i];
                count1 = 1;
            } else if(count2==0){
                num2 = nums[i];
                count2 = 1;
            } else {
                count1--;
                count2--;
            }
        }
        count1=0; count2=0;
        for(int i=0; i<nums.length; i++){
            if(nums[i]==num1) count1++;
            else if(nums[i]==num2) count2++;
        }
        List<Integer> ans = new ArrayList<>();
        if(count1>nums.length/3) ans.add(num1);
        if(count2>nums.length/3) ans.add(num2);
        return ans;
    }
}