1732. Find the Highest Altitude

Description of 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.

Constraints:

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

Solution

Code (Rust)

impl Solution {
    pub fn largest_altitude(gain: Vec<i32>) -> i32 {
        let mut altitude = 0;
        let mut max = altitude;
        
        for g in gain.into_iter(){
            max = max.max(altitude);
            altitude += g;
        }

        // remember the last element
        return max.max(altitude);
    }
}

Complexity

  • n is length of gain

Time Complexity

  • \(T(n) = \Theta(n)\)

Auxiliary Space

  • \(S(n) = O(1)\)