剑指offer-数组中出现次数超过一半的数字

class Solution {
public:
    int MoreThanHalfNum_Solution(vector<int> numbers) {
        int len = numbers.size();
        if(len==0) return 0;
        sort(numbers.begin(),numbers.end());
        int mid = numbers[len/2];
        int sum=0;
        for(int i=0;i<len;i++)
        {
            if(numbers[i]==mid)
                sum++;
        }
        if(sum > len/2)
            return mid;
        return 0;
    }
};