AdventOfCode2024/src/day4/puzzle1.typ

91 lines
1.7 KiB
Typst

#import "/src/utils.typ": *
#import "@preview/cetz:0.3.1": canvas, draw
#let check-xmas(lines, ox, oy) = {
let w = lines.first().len()
let h = lines.len()
let dirs = ()
for dy in (-1, 0, 1) {
for dx in (-1, 0, 1) {
if dx == 0 and dy == 0 {
continue
}
let buffer = ""
let x = ox
let y = oy
for i in range(4) {
buffer += lines.at(y).at(x)
x += dx
y += dy
if (
not "XMAS".starts-with(buffer) or
x < 0 or x >= w or
y < 0 or y >= h
) {
break
}
}
if buffer == "XMAS" {
dirs.push((dx, dy))
}
}
}
return dirs
}
#let solve(input) = {
let lines = input.split("\n")
let w = lines.first().len()
let h = lines.len()
let total = 0
for y in range(h) {
for x in range(w) {
if lines.at(y).at(x) == "X" {
total += check-xmas(lines, x, y).len()
}
}
}
return total
}
#let visualize(input) = {
let lines = input.split("\n")
let w = lines.first().len()
let h = lines.len()
canvas({
for y in range(h) {
for x in range(w) {
if lines.at(y).at(x) == "X" {
let key = str(x) + "-" + str(y)
let dirs = check-xmas(lines, x, y)
draw.on-layer(2, {
for (dx, dy) in dirs {
draw.line(
(x + dx * 0.2, y + dy * 0.2),
(x + dx * 2.8, y + dy * 2.8),
stroke: red,
fill: red,
mark: (end: ">")
)
}
})
}
draw.content(
(x, y),
lines.at(y).at(x)
)
}
}
})
}
#show-puzzle(
4, 1,
solve,
example: 18,
visualize: visualize
)