#adventOfCode day 12 in #LuaLang

https://gitlab.cs.washington.edu/fidelp/advent-of-code-2025/-/blob/main/12.lua

• PC - 2ms
• Raspberry Pi 2: 76ms
• #ti92 Plus: Crashed

I wasn't expecting that to work!

And as usual, AoC is a good source of stressing cases to expose crashes/bugs in the #ticalc Lua port :p

Merry Christmas!
This is the first Advent of Code I've ever completed!

#adventOfCode day 10 in #LuaLang and #Mathematica

https://gitlab.cs.washington.edu/fidelp/advent-of-code-2025/-/blob/main/10.lua

• PC - 487 ms
• Raspberry Pi 4: a few seconds
• #ti92 Plus: N/A

Ok, finally all caught up and looking forward to some sleep and Day 12!

After a night and day in math land confusing myself with row echelon matrices and intersecting N-spaces, I remembered that I have a Raspberry Pi that for some reason has free preinstalled Mathematica.

So my Lua program code-gens a Mathematica program, which then runs on the Pi to solve Part B!

This generated code is checked in if you want to look at it - it's several thousand lines of simultaneous equations being solved with constraints applied: https://gitlab.cs.washington.edu/fidelp/advent-of-code-2025/-/blob/main/10.m

Given all that, it's pleasantly fast. Mathematica over VNC on wifi is pretty laggy but the actual execution couldn't have taken more than a second or two!

(Yes, I did attempt to solve the equations on the TI-92+ #ticalc, as it has a very capable computer algebra system, but I couldn't figure out how to apply all the necessary constraints -- maybe later.)

#adventOfCode day 7 in #LuaLang

https://gitlab.cs.washington.edu/fidelp/advent-of-code-2025/-/blob/main/07.lua

• PC - 1.5 ms
• Raspberry Pi 2: 41 ms
• #ti92 Plus: >18 min

After a couple of days where the TI-92+ has been disagreeable, it was refreshing to get a puzzle where the Lua solution Just Works without memory exhaustion. Though, speedy it ain't. And when I got my camera out to photograph the real calc, I found it had crashed, so you get a boring emulator screenshot of it working instead.... ;)

I'm a little confused why it's this slow on the #ticalc: something about it seems difficult compared to the other working examples. I think it's because my approach generates lots of garbage so Lua's gc is working hard.

#adventOfCode day 6 in #LuaLang

https://gitlab.cs.washington.edu/fidelp/advent-of-code-2025/-/blob/main/06.lua

• PC - 5.1 ms
• Raspberry Pi 2: 147 ms
• #ti92 Plus: out of memory

I'm steadily accumulating a backlog that I need to rewrite into C for the #ticalc. I'm really jonesing to switch back to the DOS-based HP 200LX palmtop... 640K RAM feels mighty spacious in comparison to the calculator. Maybe in my copious spare time I need to track down the memory corruption problem that's stopping the 16-bit MS-DOS Lua from working.

#adventOfCode day 5 in #LuaLang

https://gitlab.cs.washington.edu/fidelp/advent-of-code-2025/-/blob/main/05.lua

• PC - 1.7 ms
• Raspberry Pi 2: 49 ms
• #ti92 Plus: out of memory

The #ticalc doesn't make it through input parsing before exhausting memory. It will be necessary to rewrite in C again.