Generative AI for Software Development
Generative AI for Software DevelopmentIn this doc we will talk about Generative AI and how it can be used in software development. This is not about how to build a generative AI model, but how to use existing generative AI models to help with software development.
This is a note for the course Generative AI for Software Development on Coursera.
Concept1. What is Generative AI?Generative AI is a type of AI that can generate new data that looks like it came from the original dataset. It can be u ...
bit operation
Bit OperationIn this doc we will talk about bit operations basics and some common bit manipulation tricks that can help solve problems in programming & interviews.
位运算的主要思想是五种运算：与(&)，或(|)，异或(^)，左移(<<)，右移(>>)。位运算的常用技巧如下：
n &（n-1）能够消灭n中最右侧的一个1。右移：除以2， 左移：乘以2。异或性质：交换律，0^a=a, a^a=0;
wheretolive2024
2024，我们该去哪儿生活？我们将在这里对感兴趣的城市进行一些深入的探索和比较，通过建立一个评分系统，来帮助我们决定2024年我们应该去哪里生活。
因素
在那里的收入，目前的现金流，买房首付大概多少，房贷每月多少；
一些固定的生活成本，房子、车子的维护，水电网，房产税，保险，以及其他一些固定的开销；
精神生活：旅游，养狗狗，聚餐，运动花销，其他娱乐活动；
生娃养娃成本，孩子学费，以及其他一些可能的支出；
医疗：痘痘、多囊、其他可能的医疗支出；
父母养老：每年能为父母养老存多少，以及其他可能的支出；
当地的天气、气候；
Numbers
NumbersIn this doc we will talk about some interesting facts about numbers and how to deal with them in programming.
Basic ConceptsPrime NumbersPrime numbers are numbers that are greater than 1 and have no divisors other than 1 and themselves. They are the building blocks of all other numbers and have many interesting properties.
质数是大于1且除了1和自身外没有其他因子的数。
How to check if a number is prime (ignore brute force method):
Method 1: Check divisibility up to the square root of the number.
1234567891011 ...
Memory Management
Memory ManagementIn this doc we will talk about memory management in iOS and other operating systems.
Stack and Heap1. StackThe stack is a region of memory that is used to store local variables and function call information. It is a LIFO (Last In First Out) data structure, which means that the last item pushed onto the stack is the first item popped off the stack.
The stack is managed automatically by the operating system, and memory is allocated and deallocated in a strict order. When a functio ...
Swift Attributes
Swift AttributesIn this doc we will talk about some attributes in Swift that can help you write better code.
@autoclosure@autoclosure is an attribute that automatically wraps an expression in a closure. It is useful when you want to delay the evaluation of an expression.
Code without @autoclosure:
1234567func logIfTrue(_ predicate: () -> Bool) { if predicate() { print("True") }}logIfTrue({ 2 > 1 })
Code with @autoclosure:
1234567func lo ...
Dictionary in Swift
Dictionary in SwiftIn this doc we will talk about something that we need pay attention to when we are dealing with dictionaries in programming.
Convenient Methods1. Dictionary Initialization From SequenceIn Swift, you can initialize a dictionary from a sequence of key-value pairs. The sequence can be an array of tuples or a dictionary.
12let arr = [(1, "a"), (2, "b"), (3, "c")]let dict = Dictionary(uniqueKeysWithValues: arr)
It’s helpful to convert from an array to ...
DFS in Programming
DFSIn this doc I will record some generic tricks and tips to implement Depth First Search (DFS) in programming, as well as some problems I hit when I was solving problems with DFS.
Topological SortGeneric Idea拓扑排序（Topological Sort）是一种用于有向无环图（DAG, Directed Acyclic Graph）的线性排序，使得对于图中的每一条有向边 (u, v)，顶点 u 在 v 之前出现在排序中。简而言之，拓扑排序就是对一个有向图进行排序，使得每个节点都在它所有前驱节点之后出现。
拓扑排序的输出结果是一个线性序列，可以用于解决很多实际问题，例如编译器的依赖关系分析、任务调度等。这个结果不是唯一的，一个有向无环图可能有多个拓扑排序。
拓扑排序的具体实现步骤通常使用深度优先搜索（DFS）或基于入度的贪心算法（Kahn’s Algorithm）。以下是一个使用 DF ...
Arrays in Swift
Arrays in SwiftIn this doc we will talk about something that we need pay attention to when we are dealing with arrays in programming.
Time Complexity1. Reverse an array can be more efficient than removing then insertingCompared to reverse an array, removing k elements from the end of an array then inserting them to the beginning of the array one by one is more time consuming.
Even though both of them are O(n), the latter one is more time consuming because it involves more operations and makes mo ...
观intern demo有感
今天参加了隔壁组intern的中期demo，分为两个不同的小项目，虽然并不能在此记录具体的内容，但是每一个都很有趣，intern在短短几周的时间内完成了很漂亮的demo，为他点赞。这也让我仿佛看到了自己选择投身技术行业的初衷、对快速实现有趣想法的热情。
身在一个大公司，很多时候我们想要做什么要经过无数的cross-team的讨论和协调，尽管项目本身的scope可能并不大，难度可能并不高，但是往往由于各种团队的不同需求和意见，会让一个小项目变得复杂起来，有些时候也会导致同一件事情被反复讨论，最终可能还是无法达成一致。就算达成一致，也有可能后面再被一个新的团队或者成员提出异议，导致又要重新讨论。更不要提有些时候碰到一些很难缠的团队leader，不愿意对需要的support做出承诺，导致整个项目进度被拖延。
我绝不是说这种cross-team的讨论和协调是不重要的，相反，我认为这是非常重要的，首先每个团队都应该对自己做出的commitment负责，其次，通过这种讨论和协调，可以让每个团队更好地了解其他团队的需求和意见，从不同的角度思考问题，也能尽可能地避免edge case被忽略。当然在大公 ...