added visualization + minor fixes

src/day1/puzzle2.typ

@@ -1,4 +1,5 @@
 #import "/src/utils.typ": *
+#import "@preview/cetz:0.3.1": canvas, draw
 
 #let solve(input) = {
   let lines = input.split("\n")
@@ -29,8 +30,57 @@
   return total
 }
 
+#let visualize(input) = {
+  let lines = input.split("\n")
+  let (l1, l2) = ((), ())
+  let reg = regex("^(\d+)\s+(\d+)$")
+  for line in lines {
+    let digits = line.match(reg)
+    l1.push(digits.captures.first())
+    l2.push(digits.captures.last())
+  }
+
+  let unique = l1.dedup()
+  let colors = (red,green)
+  canvas({
+    for (i, n) in l1.enumerate() {
+      let y = -0.9 * i
+      draw.circle(
+        (0, y),
+        radius: 0.35,
+        stroke: black,
+        name: "l" + str(i)
+      )
+      draw.content((0, y), n)
+    }
+    for (i, n) in l2.enumerate() {
+      let y = -0.9 * i
+      draw.circle(
+        (4, y),
+        radius: 0.35,
+        stroke: black,
+        name: "r" + str(i)
+      )
+      draw.content((4, y), n)
+    }
+    for (i, a) in l1.enumerate() {
+      for (j, b) in l2.enumerate() {
+        if a == b {
+          draw.line(
+            "l" + str(i),
+            "r" + str(j),
+            stroke: colors.at(unique.position(n => n == a)) + 1.5pt,
+            mark: (end: "straight")
+          )
+        }
+      }
+    }
+  })
+}
+
 #show-puzzle(
-  1,
+  1, 2,
   solve,
-  example: 31
+  example: 31,
+  visualize: visualize
 )