2962.js

/** ------------------------------------------------------------------------------
 * 
 * 2962. Count Subarrays Where Max Element Appears at Least K Times
 * Topics: Sliding Window
 * https://leetcode.com/problems/count-subarrays-where-max-element-appears-at-least-k-times/description/?envType=daily-question&envId=2025-04-29
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {number[]} nums
 * @param {number} k
 * @return {number}
 */
var countSubarrays = function (nums, k) {
  let max = 0
  let maxCount = 0
  let result = 0
  let leftNear = 0

  for (let i = 0; i < nums.length; i++) {
    let num = nums[i]
    if (num > max) {
      max = num
      maxCount = 1
      result = 0
      leftNear = 0
    } else if (num === max) {
      maxCount++
    }

    if (maxCount < k) {
      continue
    }

    while (maxCount !== k || nums[leftNear] !== max) {
      if (nums[leftNear] === max) {
        maxCount--
      }

      leftNear++
    }

    result += leftNear + 1
  }

  return result
}

console.log(countSubarrays([1, 3, 2, 3, 3], 2))