Maximum Average Subarray I

Description

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

 

Solution(javascript)

const findMaxAverage = function (nums = [], k) {
  let sum = nums.slice(0, k).reduce((acc, v) => acc + v, 0)
  let max = sum
  for (let i = 1; i <= nums.length - k; i++) {
    sum = sum + nums[i + k - 1] - nums[i - 1]
    max = Math.max(max, sum)
  }
  return max / k
}