题解 | #数组中出现次数超过一半的数字#

简单的hash表查找法

#include <unordered_map>
class Solution {
  public:
    int MoreThanHalfNum_Solution(vector<int>& numbers) {
        unordered_map<int, int> hash;
        int len = numbers.size();
        for (int i = 0; i < len; i++) {
            if (hash.find(numbers[i]) == hash.end()) {
                hash[numbers[i]] = 1;
            } else {
                hash[numbers[i]]++;
            }
            if (hash[numbers[i]] > len / 2) {
                return numbers[i];
            }
        }
        return -1;
    }
};