1732. Find the Highest Altitude

There is a biker going on a road trip. The road trip consists of n + 1 points at different altitudes. The biker starts his trip on point 0 with altitude equal 0.

You are given an integer array gain of length n where gain[i] is the net gain in altitude between points i and i + 1 for all (0 <= i < n). Return the highest altitude of a point.

class Solution {
public:
    int largestAltitude(vector<int>& gain) {
        int res = 0, now = 0;
        for(auto g : gain) res = max(res, now += g);
        return res;
    }
};