maxofsubarrays.js

function maxSubarray(arr, k) {
  const result = []; // to store maximum values of subarrays
  const queue = []; // to store indices of elements in the current subarray

  for (let i = 0; i < arr.length; i++) {
    // remove elements that are outside of the current window
    if (queue.length > 0 && queue[0] <= i - k) {
      queue.shift();
    }

    // remove elements that are smaller than the current element
    while (queue.length > 0 && arr[i] >= arr[queue[queue.length - 1]]) {
      queue.pop();
    }

    // add current element to the queue
    queue.push(i);

    // add maximum element to the result array if the current window is complete
    if (i >= k - 1) {
      result.push(arr[queue[0]]);
    }
  }

  return result;
}