Simple + Understandable;
\n# Code\n\nclass Solution {\npublic:\n    long long findTheArrayConcVal(vector<int>& nums) {\n        vector<string> s;\n        int sz = nums.size();\n       
\n# Code\n```\nclass Solution {\npublic:\n    long long findTheArrayConcVal(vector<int>& nums) {\n        vector<string> s;\n        int sz = nums.size();\n        if(sz%2==0)sz=sz/2;\n        else sz = (sz/2)+1;\n        for(int i = 0; i < sz; i++){\n            if(nums.size()==1)s.push_back(to_string(nums[0]));\n            else{\n                string first = to_string(nums[0]);\n                string last = to_string(nums[nums.size()-1]);\n\n                s.push_back(first+last);    \n\n                nums.erase(nums.begin());\n                nums.pop_back();\n            }\n        }\n\n        long long int ans = 0;\n        for(int i = 0; i < s.size(); i++){\n            ans += stoi(s[i]);\n        }\n        return ans;\n    }\n};\n```
['C++']