数组中只出现一次的数字

C++ 哈希 一次循环

class Solution {
public:
    void FindNumsAppearOnce(vector<int> data,int* num1,int *num2) {
        map<int, int> m;
        for(int i = 0; i < data.size(); i++)
        {
            if(!m.count(data[i]))
                m[data[i]]++;
            else
                m.erase(m.find(data[i]));
        }
        map<int, int>::iterator it = m.begin();
        *num1 = it->first;
        *num2 = (++it)->first;
    }
};