maximum_average_subarray.cpp

/*You are given an integer array nums consisting of n elements, and an integer k.

Find a contiguous subarray whose length is equal to k that has the maximum average value and return this value. Any answer with a calculation error less than 10-5 will be accepted.

Example 1:

Input: nums = [1,12,-5,-6,50,3], k = 4
Output: 12.75000
Explanation: Maximum average is (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75*/
#include <bits/stdc++.h>

using namespace std;
double findMaxAverage(vector<int>& nums, int k) {
        int i=0,j=0;
        double ans=0,maxi=INT_MIN;
        while(j<nums.size()){
            ans+=nums[j];
            if(j-i+1<k)
                j++;
            else if(j-i+1==k){
                maxi=max(maxi,ans);
                ans=ans-nums[i];
                i++;
                j++;
            }
        }
        return maxi/k;
}
int main(){
    int n,k;
    cin>>n>>k;
    vector<int> arr(n);
    for(int i=0;i<n;i++){
        cin>>arr[i];
    }
    double ans=findMaxAverage(arr,k);
    cout<<ans<<endl;
    return 0;
}