题解 | #数组中出现次数超过一半的数字#

import java.util.*;
import java.util.stream.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param numbers int整型一维数组 
     * @return int整型
     */
    public int MoreThanHalfNum_Solution (int[] numbers) {
        // write code here
        Map<Integer, Integer> hm = new HashMap<>();
        for (int i : numbers){
            if (hm.keySet().contains(Integer.valueOf(i))){
                hm.put(i, hm.get(i)+1);
            }else{
                hm.put(i, 1);
            }
        }
        int maxAppearance = Collections.max(hm.values());
        boolean isEven = numbers.length % 2 == 0 ? true : false;
        boolean hasSolve = false;
        if (isEven){
            if (maxAppearance > numbers.length/2){
                hasSolve = true;
            }
        }else{
            if (maxAppearance >= numbers.length/2){
                hasSolve = true;
            }
        }
        if (hasSolve){
            List<Integer> key = hm.entrySet().stream().filter(entry -> Integer.valueOf(maxAppearance).equals(entry.getValue())).map(Map.Entry::getKey).collect(Collectors.toList());
            return key.get(0);
        }
        return -1;
        
    }
}