Answer 1

一次遍历

function findLongest(str) {
  if (!str) return {}
  let count = 0
  let maxCount = 0
  let cur = str[0]
  let res = {}
  for (let i = 0; i < str.length; i++) {
    const s = str[i]
    if (s === cur) {
      count++
      if (count > maxCount) {
        res = { [s]: count }
        maxCount = count
      }
      if (count === maxCount) {
        res[s] = count
      }
    } else {
      count = 1
      cur = s
    }
  }
  return res
}

时间复杂度O(n), 空间复杂度O(1)

你这个 输入 ab 返回 {a:1}

Answer 2

vue源码哪里可以看到父组件要等待子组件完成之后 才处罚自身装载啊

Answer 3

打卡