day 17 part 1 done, part 2 requires more thought

.aocrunner.json

@@ -253,9 +253,11 @@
     },
     {
       "part1": {
-        "solved": false,
+        "solved": true,
         "result": null,
-        "attempts": [],
+        "attempts": [
+          "1,4,0,1,1,0,1,0,3"
+        ],
         "time": null
       },
       "part2": {

README.md

@@ -27,7 +27,7 @@
 [![Day](https://badgen.net/badge/14/%E2%98%85%E2%98%86/yellow)](src/day14)
 [![Day](https://badgen.net/badge/15/%E2%98%85%E2%98%85/green)](src/day15)
 [![Day](https://badgen.net/badge/16/%E2%98%85%E2%98%85/green)](src/day16)
-![Day](https://badgen.net/badge/17/%E2%98%86%E2%98%86/gray)
+[![Day](https://badgen.net/badge/17/%E2%98%85%E2%98%86/yellow)](src/day17)
 ![Day](https://badgen.net/badge/18/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/19/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/20/%E2%98%86%E2%98%86/gray)
@@ -181,9 +181,9 @@ Both parts: 132.546ms
 
 ```
 Day 17
-Time part 1: -
+Time part 1: 0.064ms
 Time part 2: -
-Both parts: -
+Both parts: 0.064ms
 ```
 
 ```
@@ -243,8 +243,8 @@ Both parts: -
 ```
 
 ```
-Total stars: 31/50
+Total stars: 32/50
-Total time: 150841.213ms
+Total time: 150841.277ms
 ```
 
 <!--/RESULTS-->

src/day17/README.md

@@ -0,0 +1,9 @@
+# 🎄 Advent of Code 2024 - day 17 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2024/day/17)
+
+## Notes
+
+...

src/day17/index.ts

@@ -0,0 +1,137 @@
+import run from "aocrunner"
+
+const parseInput = (rawInput: string) => {
+  const [registers, program] = rawInput.split('\n\n')
+  return {
+    registers: registers.split('\n').map(r => BigInt(r.split(": ")[1])),
+    program: program.split(': ')[1].split(',').map(Number)
+  }
+}
+
+const mod = (a: bigint, b: bigint) => ((a % b) + b) % b
+
+const explainProgram = (program: number[]) => {
+  let explanation = ""
+  const ops = [
+    x => `A = A >> ${combo(x)}`,
+    x => `B = B XOR ${x}`,
+    x => `B = ${combo(x)} % 8`,
+    x => `GOTO ${x}`,
+    x => `B = B XOR C`,
+    x => `Output ${combo(x)} % 8`,
+    x => `B = B >> ${combo(x)}`,
+    x => `C = C >> ${combo(x)}`,
+  ]
+  const combo = x => "0123ABC"[x]
+  for (let i = 0; i < program.length; i += 2) {
+    const op = ops[program[i]](program[i+1])
+    explanation += `${i}: ${op}\n`
+  }
+  return explanation.trim()
+}
+
+const execute = (registers: bigint[], program: number[]) => {
+  let seenStates = new Set<string>()
+  let [a, b, c] = registers
+  let pointer = 0
+  const output: number[] = []
+  const getCombo = (n: number) => [0n, 1n, 2n, 3n, a, b, c][n]
+  const ops: ((operand: number) => void)[] = [
+    n => { // adv
+      a = a >> getCombo(n)
+      pointer += 2
+    },
+    n => { // bxl
+      b = b ^ BigInt(n)
+      pointer += 2
+    },
+    n => { // bst
+      b = mod(getCombo(n), 8n)
+      pointer += 2
+    },
+    n => { // jnz
+      pointer = a === 0n ? pointer + 2 : n
+    },
+    n => { // bxc
+      b = b ^ c
+      pointer += 2
+    },
+    n => { // out
+      output.push(Number(mod(getCombo(n), 8n)))
+      pointer += 2
+    },
+    n => { // bdv
+      b = a >> getCombo(n)
+      pointer += 2
+    },
+    n => { // cdv
+      c = a >> getCombo(n)
+      pointer += 2
+    },
+  ]
+  while (true) {
+    const thisState = [a,b,c,pointer].join()
+    if (seenStates.has(thisState)) {
+      return 'LOOP'
+    }
+    if (pointer >= program.length) {
+      return output.join()
+    }
+    const opcode = program[pointer]
+    const operand = program[pointer + 1]
+    ops[opcode](operand)
+  }
+}
+
+const part1 = (rawInput: string) => {
+  const { registers, program } = parseInput(rawInput)
+  return execute(registers, program)
+}
+
+
+const part2 = (rawInput: string) => {
+  const { registers: [_a, b, c], program } = parseInput(rawInput)
+  console.log(explainProgram(program))
+  // const target = program.join()
+  // let i = 1n
+  // while (true) {
+  //   const result = execute([i, b, c], program)
+  //   if (result.length < target.length) i *= 2n
+  //   if (result === target) {
+  //     return i
+  //   }
+  //   console.log(`${i} ${result}`)
+  //   i += 1n
+  // }
+}
+
+run({
+//   part1: {
+//     tests: [
+//       {
+//         input: `Register A: 729
+// Register B: 0
+// Register C: 0
+
+// Program: 0,1,5,4,3,0`,
+//         expected: `4,6,3,5,6,3,5,2,1,0`,
+//       },
+//     ],
+//     solution: part1,
+//   },
+  part2: {
+    tests: [
+      {
+        input: `Register A: 2024
+Register B: 0
+Register C: 0
+
+Program: 0,3,5,4,3,0`,
+        expected: 117440,
+      },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+  onlyTests: false,
+})