# Maximum Average Subarray I Problem

## Description

LeetCode Problem 643.

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:

``````1
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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
``````

Example 2:

``````1
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Input: nums = [5], k = 1
Output: 5.00000
``````

Constraints:

• n == nums.length
• 1 <= k <= n <= 10^5
• -10^4 <= nums[i] <= 10^4

## Sample C++ Code

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class Solution {
public:
double findMaxAverage(vector<int>& nums, int k) {
double sum = 0, res = INT_MIN;
for (int i = 0; i < nums.size(); i++) {
if (i < k)
sum += nums[i];
else {
res = max(sum, res);
sum += nums[i] - nums[i-k];
}
}
res = max(sum, res);
return res / k;
}
};
``````