2219. Maximum Sum Score of Array

You are given a 0-indexed integer array nums of length n.

The sum score of nums at an index i where 0 <= i < n is the maximum of:

• The sum of the first i + 1 elements of nums.
• The sum of the last n - i elements of nums.

Return the maximum sum score of nums at any index.

class Solution {
public:
    long long maximumSumScore(vector<int>& nums) {
        long long rsum = accumulate(begin(nums), end(nums), 0ll), lsum = 0, res = LLONG_MIN;
        for(auto& n : nums) {
            lsum += n;
            res = max({res, lsum, rsum});
            rsum -= n;
        }
        return res;
    }
};