3105.js

/** ------------------------------------------------------------------------------
 * 
 * 3105. Longest Strictly Increasing or Strictly Decreasing Subarray
 * Topics: Array
 * https://leetcode.com/problems/longest-strictly-increasing-or-strictly-decreasing-subarray/?envType=daily-question&envId=2025-02-03
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {number[]} nums
 * @return {number}
 */
var longestMonotonicSubarray = function (nums) {
  const n = nums.length
  if (n < 2) return n

  let max = 1
  let currInc = 1
  let currDec = 1

  for (let i = 1; i < n; i++) {
    if (nums[i - 1] < nums[i]) {
      currInc++
      max = Math.max(max, currInc)
      currDec = 1
    } else if (nums[i - 1] > nums[i]) {
      currDec++
      max = Math.max(max, currDec)
      currInc = 1
    } else {
      currInc = 1
      currDec = 1
    }
  }

  return max
}

console.log(longestMonotonicSubarray([1, 4, 3, 3, 2]))