export function decompressString(s: string): string {
  const nums = []
  const words = []
  let num = 0
  let word = ''
  for (let i = 0; s.length > i; i++) {
    const char = s[i]
    if (Number(char)) {
      num = Number(char)
    } else if (char === '[') {
      nums.push(num)
      words.push(word)
      num = 0
      word = ''
    } else if (char === ']') {
      const times = nums.pop()
      const prevWord = words.pop()
      word = prevWord + word.repeat(times)
    } else {
      word += char
    }
  }
  return word
}