感觉Leetcode出书了以后judge速度快了不少，可是新出的题目质量不大好

Given an array of size n, find the majority element. The majority element is the element that appears more than ? n/2 ? times.

You may assume that the array is non-empty and the majority element always exist in the array.

    int majorityElement(vector<int> &num) {
        sort(num.begin(), num.end());
        return num[num.size()/2];
    }