DSA using JavaScript

Time Complexity: O(n^2), where n is the length of nums (due to nested loops).
Space Complexity: O(1), as only variables for tracking the length are used.

Sliding Window

function longestEvenOddSubarray(nums, threshold) {
  let maxLength = 0;

  for (let l = 0; l < nums.length; l++) {
    if (nums[l] % 2 !== 0 || nums[l] > threshold) continue;

    let currentLength = 1;
    for (let r = l + 1; r < nums.length; r++) {
      if (nums[r] > threshold || nums[r] % 2 === nums[r - 1] % 2) break;
      currentLength++;
    }

    maxLength = Math.max(maxLength, currentLength);
  }

  return maxLength;
}

const nums = [3,2,5,4];
const threshold = 5;
console.log(longestEvenOddSubarray(nums, threshold));  // Output: 3

function longestEvenOddSubarray(nums, threshold) {
  let maxLength = 0;
  let l = 0;

  for (let r = 0; r < nums.length; r++) {
    if (nums[r] > threshold || (r > 0 && nums[r] % 2 === nums[r - 1] % 2)) {
      l = r + (nums[r] % 2 === 0 && nums[r] <= threshold ? 0 : 1);
      continue;
    }

    maxLength = Math.max(maxLength, r - l + 1);
  }

  return maxLength;
}

const nums = [2,3,4,5];
const threshold = 4;
console.log(longestEvenOddSubarray(nums, threshold));  // Output: 3