3442.js

/** ------------------------------------------------------------------------------
 * 
 * 3442. Maximum Difference Between Even and Odd Frequency I
 * Topics: Hash Table
 * https://leetcode.com/problems/maximum-difference-between-even-and-odd-frequency-i/description/?envType=daily-question&envId=2025-06-10
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {string} s
 * @return {number}
 */
var maxDifference = function (s) {
  const map = new Map()
  let odd = -Infinity
  let even = Infinity

  for (const word of s) {
    /* map[word] = (map[word] || 0) + 1;   */
    map.set(word, (map.get(word) || 0) + 1)
  }

  for (const word of map.values()) {
    if (word % 2 !== 0) {
      odd = Math.max(odd, word)
    } else {
      even = Math.min(even, word)
    }
  }

  return odd - even
}

console.log(maxDifference("aaaaabbc"))