781.js

/** ------------------------------------------------------------------------------
 * 
 * 781. Rabbits in Forest
 * Topics: Hash Table, Greedy
 * https://leetcode.com/problems/rabbits-in-forest/description/?envType=daily-question&envId=2025-04-20
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {number[]} answers
 * @return {number}
 */

var numRabbits = function (answers) {
  const map = new Map()
  for (let answer of answers) {
    map.set(answer, (map.get(answer) || 0) + 1)
  }
  let count = 0

  for (let [x, n] of map) {
    const group = x + 1
    const groupCount = Math.ceil(n / group)
    count += groupCount * group
  }
  return count
}

console.log(numRabbits([1, 1, 2]))