Pow and Log
We use pow and log10 to avoid string conversion.\n\n## One-Liner\nOne-liner for my functional frieds. For those who are yet to embrace this, see the raw loops v
We use `pow` and `log10` to avoid string conversion.\n\n## One-Liner\nOne-liner for my functional frieds. For those who are yet to embrace this, see the raw loops version below. \n\n**C++**\n```cpp\nlong long findTheArrayConcVal(vector<int>& n) {\n    return transform_reduce(begin(n), begin(n) + n.size() / 2, rbegin(n), 0LL, plus{}, [](int l, int r){\n        return l * pow(10, (int)log10(r) + 1);}) \n        + accumulate(begin(n) + n.size() / 2, end(n), 0LL);\n} \n```\n\n## Raw Loops\n**C++**\n```cpp\nlong long findTheArrayConcVal(vector<int>& nums) {\n    long long res = 0, sz = nums.size();\n    for (int i = 0, j = sz - 1; i <= j; ++i, --j)\n        if (i < j)\n            res += nums[i] * pow(10, (int)log10(nums[j]) + 1) + nums[j];\n        else\n            res += nums[i];\n    return res;\n}\n```
['C']