# Maximum Average Subarray I in C++

C++Server Side ProgrammingProgramming

Suppose we have an array with n elements, we have to find the contiguous subarray of given length k that has the maximum average value. We have to return the maximum average value.

So, if the input is like [1,13,-5,-8,48,3] and k = 4, then the output will be 12.0, as (13-5-8+48)/4 = 12.0.

To solve this, we will follow these steps −

• sum := 0

• for initialize i := 0, when i < k, update (increase i by 1), do −

• sum := sum + nums[i]

• maxi := sum

• for initialize i := k, when i < size of nums, update (increase i by 1), do −

• sum := sum + nums[i] - nums[i - k]

• if sum > maxi, then −

• maxi := sum

• return maxi / k

## Example

Let us see the following implementation to get better understanding −

Live Demo

#include <bits/stdc++.h>
using namespace std;
class Solution {
public:
double findMaxAverage(vector<int>& nums, int k) {
int sum = 0;
for (int i = 0; i < k; i++) {
sum += nums[i];
}
double maxi = sum;
for (int i = k; i < nums.size(); i++) {
sum += nums[i] - nums[i - k];
if (sum > maxi) {
maxi = sum;
}
}
return maxi / k;
}
};
main(){
Solution ob;
vector<int> v = {1,13,-5,-8,48,3};
cout << (ob.findMaxAverage(v, 4));
}

## Input

{1,13,-5,-8,48,3}, 4

## Output

12
Published on 11-Jun-2020 15:40:10