SIMPLE TWO-POINTER C++ 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:o(n)\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:o(1)\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\n\n#define ll long long \nclass Solution {\npublic:\n    ll findTheArrayConcVal(vector<int>& nums) {\n        ll n = nums.size();\n        ll ans = 0;\n        ll i = 0;\n        ll  j = n - 1;\n        while (i < j){\n          string s =to_string(nums[i]) +to_string(nums[j]);  // concatenating num[i] and num[j]\n            ans+=stoll(s);  // Convert the concatenated string back to a int(long long) and add to ans.\n            i++;  \n            j--;  \n        }\n        if(i == j) ans+=nums[i];  // If there\'s one element left in the middle, add it to ans.\n        return ans;\n    }\n};\n```
['C++']