started day 17 puzzle 2

src/day17/puzzle1.typ

@@ -81,5 +81,7 @@
 #show-puzzle(
   17, 1,
   solve,
-  example: "4,6,3,5,6,3,5,2,1,0"
+  example: (
+    "1": "4,6,3,5,6,3,5,2,1,0"
+  )
 )

src/day17/puzzle2.typ

@@ -0,0 +1,108 @@
+#import "/src/utils.typ": *
+
+#let ADV = 0
+#let BXL = 1
+#let BST = 2
+#let JNZ = 3
+#let BXC = 4
+#let OUT = 5
+#let BDV = 6
+#let CDV = 7
+
+#let ops = ("ADV", "BXL", "BST", "JNZ", "BXC", "OUT", "BDV", "CDV")
+
+#let get-combo(regs, value) = {
+  if value >= 7 {
+    panic()
+  }
+  if value <= 3 {
+    return value
+  }
+  return regs.at(value - 4)
+}
+
+#let describe-combo(value) = {
+  if value == 7 {
+    return "<invalid>"
+  }
+  if value <= 3 {
+    return str(value)
+  }
+  return "ABC".at(value - 4)
+}
+
+#let describe(program) = {
+  let res = ""
+  res += program.map(str).join(",")
+
+  for i in range(0, program.len(), step: 2) {
+    res += "\n"
+    let op = program.at(i)
+    let val = program.at(i + 1)
+    let combo = describe-combo(val)
+
+    res += ops.at(op) + ": "
+    if op == ADV {
+      res += "A >>= " + combo
+    } else if op == BXL {
+      res += "B ^= " + str(val)
+    } else if op == BST {
+      res += "B = " + combo + " & 0b111"
+    } else if op == JNZ {
+      res += "IF A != 0 {PC = " + str(val) + "}"
+    } else if op == BXC {
+      res += "B ^= C"
+    } else if op == OUT {
+      res += "OUT(" + combo + " & 0b111)"
+    } else if op == BDV {
+      res += "B = A >> " + combo
+    } else if op == CDV {
+      res += "C = A >> " + combo
+    }
+  }
+  return res
+}
+
+#let solve(input) = {
+  let (registers, program) = input.split("\n\n")
+
+  let regs = ()
+  for line in registers.split("\n") {
+    regs.push(
+      int(
+        line.split(": ")
+            .last()
+      )
+    )
+  }
+  program = program.split(": ")
+                   .last()
+                   .split(",")
+                   .map(int)
+
+  let out = ()
+  let pc = 0
+
+  regs.first() = 0
+
+  for n in program {
+    let b = n
+  }
+  
+  return raw(block: true, describe(program))
+}
+
+Example:
+#solve(read(get-example-path(17, suffix: "2")))
+
+Input:
+#solve(get-input(17))
+
+/*
+#show-puzzle(
+  17, 2,
+  solve,
+  example: (
+    "2": 117440
+  )
+)*/