手写题盘点

广度遍历深克隆

JAVASCRIPT
1const getEmpty = (o) => {
2  if (Array.isArray(o)) return [];
3  if (o !== null && typeof o === "object") return {};
4  return o;
5};
6
7const cloneBfs = (a) => {
8  const root = getEmpty(a),
9    queue = [{ origin: a, copy: root }],
10    map = new Map();
11
12  while (queue.length) {
13    const { origin, copy } = queue.shift();
14    for (let i in origin) {
15      const empty = getEmpty(origin[i]);

限制 promise 并发数量

JAVASCRIPT
1const pLimit = (limit) => {
2  let count = 0;
3  const task = [];
4  return async (fn) => {
5    if (count >= limit) {
6      await new Promise((r) => task.push(r));
7    }
8    count++;
9    try {
10      const ret = await fn();
11      return ret;
12    } finally {
13      count--;
14      if (task.length) {
15        task.shift()();