2789. Largest Element in an Array after Merge Operations

You are given a 0-indexed array nums consisting of positive integers.

You can do the following operation on the array any number of times:

• Choose an integer i such that 0 <= i < nums.length - 1 and nums[i] <= nums[i + 1]. Replace the element nums[i + 1] with nums[i] + nums[i + 1] and delete the element nums[i] from the array.

Return the value of the largest element that you can possibly obtain in the final array.

class Solution {
public:
    long long maxArrayValue(vector<int>& nums) {
        reverse(begin(nums), end(nums));
        vector<long long> now{nums[0]};
        for(int i = 1; i < nums.size(); i++) {
            if(now.back() >= nums[i]) now.back() += nums[i];
            else now.push_back(nums[i]);
        }
        return *max_element(begin(now), end(now));
    }
};