1732_Find_the_Highest_Altitude.cpp

/*
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
*/
// Optimized Approach
// Time Complexity O(n)
// Space Complexity O(n)
class Solution {
public:
    int largestAltitude(vector<int>& gain) {
       vector<int>temp = {0};
       for(auto it:gain){
           temp.push_back(it + temp.back());
       } 
       return *max_element(temp.begin(), temp.end());
    }
}; 
// Optimized Approach
// Time Complexity O(n)
// Space Complexity O(n)
class Solution {
public:
int maxAltitude(vector<int> arr){
    int n = arr.size();
    int maxa = INT_MIN;
    for(auto x:arr){
        maxa = max(maxa,x);
    }
    return maxa;
}
    int largestAltitude(vector<int>& gain) {
        int n = gain.size();
        vector<int> ans(n+1);
        ans[0]=0;
        int k=1;
        for(int i=0;i<n;i++){
            ans[k]=gain[i]+ans[k-1];
            k++;
        }
       return maxAltitude(ans);
    }
};