package leetcode_1To300;

import java.util.ArrayList;
import java.util.List;

/**
 * 本代码来自 Cspiration，由 @Cspiration 提供
 * 题目来源：http://leetcode.com
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 * - 版权所有，转发请注明出处
 */
public class _229_MajorityElementII {
    /**
     * 229. 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.
     *
     * time : O(n)
     * space : O(1)
     *
     * @param nums
     * @return
     */
    public static List<Integer> majorityElement(int[] nums) {
        if (nums == null || nums.length == 0) {
            return new ArrayList<>();
        }
        List<Integer> res = new ArrayList<>();
        int number1 = 0, number2 = 0;
        int count1 = 0, count2 = 0;
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] == number1) {
                count1++;
            } else if (nums[i] == number2) {
                count2++;
            } else if (count1 == 0) {
                number1 = nums[i];
                count1 = 1;
            } else if (count2 == 0) {
                number2 = nums[i];
                count2 = 1;
            } else {
                count1--;
                count2--;
            }
        }
        count1 = 0;
        count2 = 0;
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] == number1) {
                count1++;
            } else if (nums[i] == number2) {
                count2++;
            }
        }
        if (count1 > nums.length / 3) {
            res.add(number1);
        }
        if (count2 > nums.length / 3) {
            res.add(number2);
        }
        return res;
    }

}