二进制手表

暴力

借助位 1 的个数。

const countOne = (n: number): number => {
  let count = 0

  while (n) {
    n &= n - 1
    count++
  }

  return count
}

function readBinaryWatch(turnedOn: number): string[] {
  const ret: string[] = []

  for (let h = 0; h < 12; h++) {
    for (let m = 0; m < 60; m++) {
      if (countOne(h) + countOne(m) === turnedOn) {
        ret.push(`${h}:${m < 10 ? '0' : ''}${m}`)
      }
    }
  }

  return ret
}