ARTS #134

Algorithm

本周选择的算法题是：Simplify Path。

规则

Given a string path, which is an absolute path (starting with a slash '/') to a file or directory in a Unix-style file system, convert it to the simplified canonical path.

In a Unix-style file system, a period '.' refers to the current directory, a double period '..' refers to the directory up a level, and any multiple consecutive slashes (i.e. '//') are treated as a single slash '/'. For this problem, any other format of periods such as '...' are treated as file/directory names.

The canonical path should have the following format:

The path starts with a single slash '/'.
Any two directories are separated by a single slash '/'.
The path does not end with a trailing '/'.
The path only contains the directories on the path from the root directory to the target file or directory (i.e., no period '.' or double period '..')

Return the simplified canonical path.

Example 1:

Input: path = "/home/"
Output: "/home"
Explanation: Note that there is no trailing slash after the last directory name.

Example 2:

Input: path = "/../"
Output: "/"
Explanation: Going one level up from the root directory is a no-op, as the root level is the highest level you can go.

Example 3:

Input: path = "/home//foo/"
Output: "/home/foo"
Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one.

Constraints:

1 <= path.length <= 3000
path consists of English letters, digits, period '.', slash '/' or '_'.
path is a valid absolute Unix path.

Solution

class Solution:
    def simplifyPath(self, path: str) -> str:
        stack = []
        for item in path.split("/"):
            if item == "..":
                if stack:
                    stack.pop()
            elif item and item != ".":
                stack.append(item)
        return "/" + "/".join(stack)

Review

I’m an Engineering Manager who can’t code

文中引用了 Google 研究的 Best Manager 十大行为：

Is a good coach
Empowers team and does not micromanage
Creates an inclusive team environment, showing concern for success and well-being
Is productive and results-oriented
Is a good communicator — listens and shares information
Supports career development and discusses performance
Has a clear vision/strategy for the team
Has key technical skills to help advise the team
Collaborates across Google
Is a strong decision maker

其中只有一项直接提到了技术能力，对小团队来说，一个好的 Tech Lead 已经足够“管理”好团队了，但当团队规模变大后（可能只是10个人），继续微观管理反而会降低团队的效率，管理的目的从专注个人能力转变为放大团队。以一年 250 个工作日为例，一个人每年有大约 2000 个工作小时，那么 10 人团队一年就是 20000 小时，放大团队的能力将显得更为重要。

Tip

学习了在 Node.js 动态加载模块的方法，并用这个方法实现了基于 GitHub 的动态事件订阅和处理：

import { resolve, parse } from 'path'
import fg from 'fast-glob'

// 动态注册事件处理器
fg.sync('*.js', { cwd: resolve(__dirname, "events"), absolute: true })
.forEach((file: string) => {
  const eventName = parse(file).name
  app.on(eventName, async (context) => {
    const eventHandler = require(file)
    eventHandler.default(context)
  })
});

圣诞节放空一下，分享一段在终端飘雪花的脚本吧：

ruby -e 'C=`stty size`.scan(/\d+/)[1].to_i;S=["2743".to_i(16)].pack("U*");a={};puts "\033[2J";loop{a[rand(C)]=0;a.each{|x,o|;a[x]+=1;print "\033[#{o};#{x}H \033[#{a[x]};#{x}H#{S} \033[0;0H"};$stdout.flush;sleep 0.1}'

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