2022.js

/** ------------------------------------------------------------------------------
 * 
 * 2022. Convert 1D Array Into 2D Array
 * Topics: Array
 * https://leetcode.com/problems/convert-1d-array-into-2d-array/description/
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {number[]} original
 * @param {number} m
 * @param {number} n
 * @return {number[][]}
 *
 * 첫 풀이
 */
var construct2DArray = function (original, m, n) {
  const len = original.length

  if (len !== m * n) return []

  const answer = []
  let arr = []
  for (let i = 0; i < len; i++) {
    arr.push(original[i])
    if (arr.length === n) {
      answer.push(arr)
      arr = []
    }
  }

  return answer
}

/**
 * 반복문 줄임
 */
var goodAnswer = function (original, m, n) {
  let result = []

  // Check if valid
  if (original.length !== m * n) return result

  let startIndex = 0
  for (let i = 0; i < m; i++) {
    result.push(original.slice(startIndex, startIndex + n))
    startIndex += n
  }

  return result
}

console.log()

/**
 * 겉멋 풀이
 */

function construct2DArray(original, m, n) {
  const l = original.length

  if (m * n !== l) return []

  const a = []

  for (let i = 0; i < l; a.push(original.slice(i, (i += n))));

  return a
}