Easy and direct solution...
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\npublic:\n    long long findTheArrayConcVal(vector<int>& nums) {\n        long long ans=0;\n        int i=0; int j = nums.size()-1;\n        while(i<j){\n            string str1= to_string(nums[i]);\n            string str2= to_string(nums[j]);\n            string str = str1 + str2;\n            long long help = stoi(str);\n            ans+=help;\n            i++;\n            j--;\n        }\n        if(i==j){\n            // string str2= to_string(nums[j]);\n            // string str= str2;\n            // long long help = stoi(str);\n            ans+=nums[j];\n        }\n        return ans;\n    }\n};\n```
['C++']