Solution

• 位运算

class Solution {
public:
    /**
     * 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 array int整型vector 
     * @return int整型vector
     */
    vector<int> FindNumsAppearOnce(vector<int>& array) {
        // write code here
        int x = 0, y = 0, n = 0, m = 1;
        // 1.遍历异或
        for (int num : array)
            n ^= num;
        // 2.循环左移，计算 m
        while ((n & m) == 0)
            m <<= 1;
        // 3.遍历分组，array & m != 0;  array & m == 0
        for (int num : array) {
            if (num & m) x ^= num;
            else y ^= num;
        }
        // 5.返回两个数字
        if (x <= y)
            return vector<int> {x, y};
        else 
            return vector<int> {y, x};
    }
};

• 利用map存储

class Solution {
public:
    vector<int> FindNumsAppearOnce(vector<int>& array) {
        // write code here
        vector<int> res;
        int n = array.size();
        if (n == 0) return res;
        
        unordered_map<int, int> umap;
        for (int num : array) {
            umap[num]++;
        }
        for (auto iter = umap.begin(); iter != umap.end(); ++iter) {
            if (iter->second == 1) {
                res.push_back(iter->first);
            }
        }
        sort(res.begin(), res.end());
        return res;
    }
};