與程式有關的遊戲三選 (1) – A=B

We're approaching the tenth day! Let's take a break and share a few games related to programming or computing. The game I want to introduce today is called A=B, which you can purchase on Steam and is available for download on both Windows and Mac.

A=B features a programming language designed by the game's protagonist, which only includes the syntax A=B. You'll need to use this limited syntax to solve various puzzles, and as you solve more puzzles, the syntax will become increasingly rich.

Let's take a look at some reviews on Steam.

Game Content

In the game, you'll encounter various puzzles, all related to string manipulation. The A=B syntax allows you to replace string A with B. For example, if the program is aaa=bbb and the string is aaabbb, the result will be bbbbbb (replacing aaa with bbb). The explanation of the syntax in the game is quite brief, so I’ll drop a PDF link for you. As the story progresses, you'll encounter more and more syntax.

Here are a few sample puzzles from the game:

1. Sorting abc

Given a string that only contains the letters a, b, and c, with a maximum length of 7, how would you write it using only the a=b syntax?

The answer to this puzzle is straightforward; you just need to enumerate the three variations:

ba=ab
ca=ac
cb=bc

If the input is: bcba

1. Match ba, replace ba with ab, resulting in the string bcab
2. Match ca, replace ca with ac, resulting in the string bacb
3. Match ba, replace ba with ab, resulting in the string abcb
4. Match cb, replace cb with bc, resulting in the string abbc

From a programming perspective, this is a problem that could typically be solved with a simple for loop or function call, but now you must tap into a bit of creativity.

2. Palindrome

In this section, a few more syntax options are available:

y=(return)false

When matching y, it returns false.

(start)a=(end)b

When matching the starting string a, it replaces the last character with b. This characteristic of the prefix altering the suffix might seem counterintuitive, but the game design will guide you to naturally learn how to use this syntax.

The task is a well-known one: determining whether a string is a palindrome, with the input consisting only of the three letters a, b, and c.

axAy=
bxBy=
cxCy=

(start)a=(end)xAy
(start)b=(end)xBy
(start)c=(end)xCy

yx=(return)false
=(return)true

At first glance, it may seem difficult to understand, but after examining the code, the core concept becomes clear.

First, if a string starting with a, b, or c is matched, the end will be transformed into the form xAy; here, xy can be replaced with other strings, indicating that it has already been processed. Assuming the input string is abba, after the first round of processing, the string will change to: bbaxAy.

At this point, executing axAy= will eliminate a set of palindromes. Ideally, all palindromes will be removed; if any remain, it will result in a situation like yx, indicating that some strings did not match.

Reflections

Playing this game doesn't require knowledge of any programming language, but it can be difficult to dive in without a basic understanding of problem-solving concepts. For software engineers, playing this game feels a bit like solving problems using a poorly designed language.

However, I think this is a good thing. We’ve become accustomed to the concepts of programming languages, and after writing loops and functions, occasionally approaching problems from a different angle can lead to greater enjoyment.

The two examples above could be solved in just a few minutes using programming languages, but implementing them using the A=B syntax requires a fair amount of thought and leads to entirely different ways of thinking to achieve the desired outcome.