[Leet Code] Find the Highest Altitude

Leetcode: https://leetcode.com/problems/find-the-highest-altitude/

Problem:

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.

Example 1:

Input: gain = [-5,1,5,0,-7]
Output: 1
Explanation: The altitudes are [0,-5,-4,1,1,-6]. The highest is 1.

Example 2:

Input: gain = [-4,-3,-2,-1,4,3,2]
Output: 0
Explanation: The altitudes are [0,-4,-7,-9,-10,-6,-3,-1]. The highest is 0

Solution:

class Solution(object):
    def largestAltitude(self, gain):
        """
        :type gain: List[int]
        :rtype: int
        """
        start = 0
        highest = 0
        for i in gain:
            start += i
            if start > highest:
                highest = start
        return highest

Explanation:

We start at 0 with a start variable. We also have a highest variable to keep track of the maximum altitude. We go through each of the numbers and add them to start, whilst also checking if start > highest each time, and assigning start to highest if so.