[LeetCode] 643. Maximum Average Subarray I

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 = 4Output: 12.75Explanation: 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].

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