C++ Hashmap O(N)
\nclass Solution {\npublic:\n    vector<int> findLonely(vector<int>& nums) {\n        unordered_map<int,int> mp;\n        for(int i=0;i<nums.size();i++) mp[nums
```\nclass Solution {\npublic:\n    vector<int> findLonely(vector<int>& nums) {\n        unordered_map<int,int> mp;\n        for(int i=0;i<nums.size();i++) mp[nums[i]]++;\n        \n        vector<int> ans;\n        \n        for(int i=0; i<nums.size();i++)\n            if((!mp.count(nums[i]+1) && !mp.count(nums[i]-1) ) && mp[nums[i]]==1)\n                    ans.push_back(nums[i]);\n        return ans;\n    }\n};\n```
['C']