Find the Highest Altitude — Day 102(Python)

Annamariya Tharayil
2 min readJan 11, 2022


Photo by ben o'bro on Unsplash

We will work on another Easy tagged question from leetcode today.

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 an altitude equal to 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.


  • n == gain.length
  • 1 <= n <= 100
  • -100 <= gain[i] <= 100

The given input array gives us the net gain in altitude. Since we need to identify the highest altitude, we need to find the altitude at the current position using the input net gain array.

Let us look into the solution.

class Solution:
def largestAltitude(self, gain: List[int]) -> int:
output = 0
curr_alt = 0
for n in gain:
curr_alt += n
output = max(curr_alt, output)
return output


Time Complexity

Since we are just traversing through the array once, the time complexity is O(N).

Space Complexity

We are not using any extra space, and hence the space complexity will be O(1).