260. 只出现一次的数字 III

class Solution {
public:
    vector<int> singleNumber(vector<int>& nums) {
        //哈希表映射，最后把只出现一次的加入数组
        unordered_map<int, int> freq;
        for (int num: nums) {
            ++freq[num];
        }
        vector<int> ans;
        for (const auto& [num, occ]: freq) {
            if (occ == 1) {
                ans.push_back(num);
            }
        }
        return ans;
    }
};

Accepted
32/32 cases passed (8 ms)
Your runtime beats 68.96 % of cpp submissions
Your memory usage beats 20.24 % of cpp submissions (10.4 MB)