day 3, made reusable

src/day03/README.md

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+# 🎄 Advent of Code 2024 - day 3 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2024/day/3)
+
+## Notes
+
+...

src/day03/index.ts

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+import run from "aocrunner"
+
+type State = {
+  mulEnabled: boolean
+  total: number
+}
+type Instruction = "do"|"don't"|"mul"
+const instructions: Record<Instruction, (state: State, args: string[]) => State> = {
+  "do": (state, _args) => {
+    return {
+      ...state,
+      mulEnabled: true
+    }
+  },
+  "don't": (state, _args) => {
+    return {
+      ...state,
+      mulEnabled: false
+    }
+  },
+  "mul": (state, [a, b]) => {
+    return {
+      ...state,
+      total: state.total + (state.mulEnabled ? parseInt(a) * parseInt(b) : 0)
+    }
+  }
+}
+
+const parseInput = (rawInput: string) => {
+  const tokenRegexp = new RegExp(`(${Object.keys(instructions).join('|')})\\(((\\d+,?)*)\\)`, 'g')
+  const matches = rawInput.matchAll(tokenRegexp)
+  return Array.from(matches).map(match => {
+    const [, instruction, parameters] = match
+    return [instruction as Instruction, parameters === "" ? [] : parameters.split(',')] as const
+  })
+}
+
+const part1 = (rawInput: string) => {
+  const input = rawInput
+  const matches = input.matchAll(/mul\((\d+),(\d+)\)/g)
+  return Array.from(matches).reduce((acc, m) => {
+    const [,a,b] = m
+    return acc + parseInt(a) * parseInt(b)
+  }, 0)
+}
+
+const part2 = (rawInput: string) => {
+  const program = parseInput(rawInput)
+  let state: State = {
+    total: 0,
+    mulEnabled: true
+  }
+  program.forEach(([instruction, parameters]) => {
+    state = instructions[instruction](state, parameters)
+  })
+  return state.total
+}
+
+run({
+  part1: {
+    tests: [
+      {
+        input: `xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))`,
+        expected: 161,
+      },
+    ],
+    solution: part1,
+  },
+  part2: {
+    tests: [
+      {
+        input: `xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))`,
+        expected: 48,
+      },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+  onlyTests: false,
+})