Leetcode刷题83-643. 子数组最大平均数 I(C++详细解法！！！)

Come from : [https://leetcode-cn.com/problems/maximum-average-subarray-i/]

1.Question

Given an array consisting of n integers, find the contiguous subarray of given length k that has the maximum average value. And you need to output the maximum average value.

Example 1 :

Input: [1,12,-5,-6,50,3], k = 4
Output: 12.75
Explanation: Maximum average is (12-5-6+50)/4 = 51/4 = 12.75

Note:

1 <= k <= n <= 30,000.
Elements of the given array will be in the range [-10,000, 10,000].

2.Answer

easy 类型题目。
我的暴力解题思路：
依次求出 K 个元素的 平均值，找出最大的即可，但是 超出时间限制。。。

超时代码如下：（比较low。。。）

class Solution {
   
public:
    double findMaxAverage(vector<int>& nums, int k) {
   
        int maxAvg = I