12: Leonardo’s Monorail

library(mistlecode)

To install `mistlecode` yourself, run `devtools::install_github('guslipkin/mistlecode')`.

 Also loading:  cipheR data.table dplyr purrr slider stringr tidyverse glue rlang R6

dt <- readLines("input.txt")

Part 1

Okay. I finally had the motivation I needed to write an AoC BASIC interpreter/runner. It’s super slow, but it works and I don’t really have to do anything besides define the registers and the functions. If you want to learn more, take a look here.

registers <- list("a" = 0L, "b" = 0L, "c" = 0L, "d" = 0L)
functions <- list(
  "cpy" = \(x, y) {
    self[[y]] <- self$val_or_index(x)
    private$.inc()
  },
  "inc" = \(x, y) {
    self[[x]] <- self[[x]] + 1
    private$.inc()
  },
  "dec" = \(x, y) {
    self[[x]] <- self[[x]] - 1
    private$.inc()
  },
  "jnz" = \(x, y) {
    x <- self$val_or_index(x)
    if (x != 0) private$.inc(y) else private$.inc()
  }
)
create_assembly(registers, functions)$run(dt, target = "a")

[1] 318009

Part 2

Just a quick change, but oh so slow…

registers <- list("a" = 0L, "b" = 0L, "c" = 1L, "d" = 0L)
create_assembly(registers, functions)$run(dt, target = "a")

[1] 9227663