题解 | #数组中出现次数超过一半的数字#

import java.util.*;


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
        // 解题思路：1.用hash
        if (numbers.length <= 2) {
            return numbers[0];
        }

        Map<Integer, Integer> numHash = new HashMap<>();
        for (int i = 0; i < numbers.length; i++) {
            if (numHash.containsKey(numbers[i])) {
                int val = numHash.get(numbers[i]) + 1;
                numHash.put(numbers[i], val);
                if (val > numbers.length / 2) {
                    return numbers[i];
                }
            } else {
                numHash.put(numbers[i], 1);
            }
        }
        return 0;
    }
}