Easy Solution || C++
Code\n\n#define ll long long\nclass Solution {\npublic:\n    ll concat(int a,int b){\n        int c=b,d=1;\n        while(c!=0){\n            d*=10;\n          
# Code\n```\n#define ll long long\nclass Solution {\npublic:\n    ll concat(int a,int b){\n        int c=b,d=1;\n        while(c!=0){\n            d*=10;\n            c/=10;\n        }\n        return (ll)(a*d+b);\n    }\n    ll findTheArrayConcVal(vector<int>& nums) {\n        ll ans=0; int l=nums.size();\n        if(l==1) return (ll)nums[0];\n        for(int i=0,j=l-1;i<j;i++,j--)\n            ans+=concat(nums[i],nums[j]);\n        if(l%2!=0)\n            ans+=nums[l/2];//since the middle element gets left in the for loop\n        return ans; \n    }\n};\n```\n# Upvote if this helped!~\n![upvote4.jpeg](https://assets.leetcode.com/users/images/b096315e-d019-4538-bc55-981cf07a83ed_1676180334.4019172.jpeg)\n
['Array', 'Math', 'C++']