135.js

/** ------------------------------------------------------------------------------
 * 
 * 135. Candy
 * Topics: Array, Greedy
 * https://leetcode.com/problems/candy/description/?envType=daily-question&envId=2025-06-02
 * 
 ------------------------------------------------------------------------------ */
function candy(ratings) {
  const n = ratings.length
  let totalCandies = n
  let index = 1

  while (index < n) {
    while (ratings[index] === ratings[index - 1]) {
      index++
    }

    let currentPeak = 0
    while (index < n && ratings[index] > ratings[index - 1]) {
      currentPeak++
      totalCandies += currentPeak
      index++
    }

    let currentValley = 0
    while (index < n && ratings[index] < ratings[index - 1]) {
      currentValley++
      totalCandies += currentValley
      index++
    }

    totalCandies -= Math.min(currentPeak, currentValley)
  }

  return totalCandies
}

console.log(candy([1, 0, 2]))