function groupByLength(words: string[]): Record<number, string[]> {
  
  const output:Record<number, string[]> = {}

  words.forEach(word => {
    const length = word.length;
    const items = output[length] ? [...output[length], word]: [word]
    output[length] = items;
  })

  return output;
}

// No modificar: necesario para evaluar el resultado.
export { groupByLength };