Sliding Window

Array or number from one position to another

Function which accepts an array of integers and n - number of consecutive elements in the array. Return max sum of n.

function maxSubarraySum(arr, num) {
    if (arr.length < num) return null
    let maxSum = 0
    let tmpSum = 0
    for (let i = 0; i < num; i++) {
        maxSum += arr[i]
    }
    tmpSum = maxSum
    for (let i = num; i < arr.length; i++) {
        tmpSum = tmpSum - arr[i - num] + arr[i]
        maxSum = Math.max(maxSum, tmpSum) 
    }
    return maxSum
}

console.log(maxSubarraySum([2,6,9,2,1,8,5,6,3], 3)) // 19