day 8 puzzle 1

progress.yaml

@@ -11,4 +11,6 @@
 6:
   stars: 2
 7:
-  stars: 2
+  stars: 2
+8:
+  stars: 1

res/examples/day8.txt

@@ -0,0 +1,12 @@
+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............

src/day3/puzzle1.typ

@@ -1,7 +1,8 @@
 #import "/src/utils.typ": *
 
+#let reg = regex("mul\((\d{1,3}),(\d{1,3})\)")
 #let solve(input) = {
-  let matches = input.matches(regex("mul\((\d{1,3}),(\d{1,3})\)"))
+  let matches = input.matches(reg)
   let total = matches.map(m => {
     m.captures.map(int)
               .product()
@@ -9,8 +10,24 @@
   return total
 }
 
+#let visualize(input) = {
+  [
+    #set text(size: 1.2em)
+    #show reg: it => {
+      let m = it.text.match(reg)
+      let v = m.captures.map(int).product()
+      math.underbrace(
+        highlight(fill: red, raw(it.text)),
+        text(size: 1.5em, str(v))
+      )
+    }
+    #raw(input)
+  ]
+}
+
 #show-puzzle(
   3, 1,
   solve,
-  example: ("1": 161)
+  example: ("1": 161),
+  visualize: visualize
 )

src/day5/puzzle1.typ

@@ -1,4 +1,5 @@
 #import "/src/utils.typ": *
+#import "@preview/cetz:0.3.1": canvas, draw
 
 #let make-rules-dict(rules) = {
   let dict = (:)
@@ -45,8 +46,82 @@
   return total
 }
 
+#let visualize(input) = {
+  let (rules, updates) = input.split("\n\n")
+  rules = rules.split("\n").map(l => l.split("|").map(int))
+  updates = updates.split("\n").map(l => l.split(",").map(int))
+
+  let total = 0
+  //let rules-dict = make-rules-dict(rules)
+
+  let diags = ()
+  for update in updates {
+    let diag = canvas(length: 3em, {
+      for (x, n) in update.enumerate() {
+        draw.circle(
+          (x, 0),
+          radius: 0.4,
+          name: str(x)
+        )
+        draw.content(
+          (x, 0),
+          str(n)
+        )
+      }
+
+      let flip = false
+      let c = 1
+      for (a, b) in rules {
+        let i = update.position(n => n == a)
+        let j = update.position(n => n == b)
+        if i == none or j == none {
+          continue
+        }
+        let anchor = if flip {".south"} else {".north"}
+        let pt-i = str(i) + anchor
+        let pt-j = str(j) + anchor
+        let col = if j < i {red} else {green}
+
+        draw.arc-through(
+          pt-i,
+          (
+            rel: (0, if flip {-c / 10} else {c / 10}),
+            to: (pt-i, 50%, pt-j)
+          ),
+          pt-j,
+          mark: (end: ">", fill: col),
+          stroke: col
+        )
+
+        flip = not flip
+        c += 1
+      }
+    })
+
+    diags.push(diag)
+
+    /*if is-update-valid(rules-dict, update) {
+      total += update.at(calc.div-euclid(update.len(), 2))
+    }*/
+  }
+
+  diags.last() = grid.cell(
+    colspan: 2 - calc.rem(diags.len() - 1, 2),
+    diags.last()
+  )
+
+  grid(
+    columns: 2,
+    stroke: (paint: black, dash: "dashed"),
+    align: center + horizon,
+    inset: 0.4em,
+    ..diags
+  )
+}
+
 #show-puzzle(
   5, 1,
   solve,
-  example: 143
+  example: 143,
+  visualize: visualize
 )

src/day8/puzzle1.typ

@@ -0,0 +1,51 @@
+#import "/src/utils.typ": *
+
+#let in-grid(w, h, x, y) = {
+  return 0 <= x and x < w and 0 <= y and y < h
+}
+
+#let solve(input) = {
+  let by-freq = (:)
+  let antinodes = ()
+
+  let grid = input.split("\n").map(l => l.clusters())
+  let w = grid.first().len()
+  let h = grid.len()
+
+  let in-grid = in-grid.with(w, h)
+
+  for y in range(h) {
+    for x in range(w) {
+      let c = grid.at(y).at(x)
+      if c == "." {
+        continue
+      }
+      if c not in by-freq {
+        by-freq.insert(c, ())
+      }
+
+      for (x2, y2) in by-freq.at(c) {
+        let (dx, dy) = (x2 - x, y2 - y)
+        let node1 = (x - dx, y - dy)
+        let node2 = (x2 + dx, y2 + dy)
+
+        if in-grid(..node1) and node1 not in antinodes {
+          antinodes.push(node1)
+        }
+
+        if in-grid(..node2) and node2 not in antinodes {
+          antinodes.push(node2)
+        }
+      }
+      by-freq.at(c).push((x, y))
+    }
+  }
+
+  return antinodes.len()
+}
+
+#show-puzzle(
+  8, 1,
+  solve,
+  example: 14
+)