maxAvgSubOne.js

// 643. Maximum Average Subarray I

// 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
// Example 2:

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

var findMaxAverage = function(nums, k) {
    let max = -Infinity
    let soFar = 0
    let start = 0

    for(let windowEnd = 0; windowEnd < nums.length; windowEnd++){
        soFar += nums[windowEnd]

        if(windowEnd - start === k-1){
            let avg = soFar/k
            max = Math.max(max, avg)
            soFar -= nums[start]
            start++
        }
    }
    return max
}

console.log(findMaxAverage([1,12,-5,-6,50,3], 4))
console.log(findMaxAverage([5], 1))