day 13

src/day13/README.md

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+# 🎄 Advent of Code 2024 - day 13 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2024/day/13)
+
+## Notes
+
+...

src/day13/index.ts

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+import run from "aocrunner"
+const parseInput = (rawInput: string) =>
+  rawInput.split("\n\n").map((machine) => {
+    return machine
+      .split("\n")
+      .map((l) => Array.from(l.matchAll(/\d+/g)).map(Number))
+  })
+
+const part1 = (rawInput: string) => {
+  const input = parseInput(rawInput)
+  let spent = 0
+  for (const machine of input) {
+    const [[adx, ady], [bdx, bdy], [prizex, prizey]] = machine
+    let minCost = Number.POSITIVE_INFINITY
+    const tried = new Set<string>()
+    const simulate = (
+      x: number,
+      y: number,
+      aPresses: number,
+      bPresses: number,
+    ) => {
+      const key = [x, y, aPresses, bPresses].join()
+      if (tried.has(key)) return
+      tried.add(key)
+      if (x > prizex || y > prizey) {
+        return
+      }
+      const cost = aPresses * 3 + bPresses
+      if (cost >= minCost) {
+        return
+      }
+      if (x === prizex && y === prizey) {
+        minCost = cost
+        return
+      }
+      simulate(x + adx, y + ady, aPresses + 1, bPresses)
+      simulate(x + bdx, y + bdy, aPresses, bPresses + 1)
+    }
+    simulate(0, 0, 0, 0)
+    if (minCost < Number.POSITIVE_INFINITY) {
+      spent += minCost
+    }
+  }
+  return spent
+}
+
+const part2 = (rawInput: string) => {
+  const input = parseInput(rawInput)
+  let spent = 0
+  for (const machine of input) {
+    const [[adx, ady], [bdx, bdy], [specx, specy]] = machine
+    const prizex = 10000000000000 + specx
+    const prizey = 10000000000000 + specy
+    const bPresses = (prizex * ady - prizey * adx) / (bdx * ady - bdy * adx)
+    const aPresses = (prizey - bPresses * bdy) / ady
+    console.log({ aPresses, bPresses })
+    if (bPresses % 1 === 0 && aPresses % 1 === 0) {
+      spent += 3 * aPresses + bPresses
+    }
+  }
+  return spent
+}
+
+run({
+  part1: {
+    tests: [
+      {
+        input: `Button A: X+94, Y+34
+  Button B: X+22, Y+67
+  Prize: X=8400, Y=5400
+
+  Button A: X+26, Y+66
+  Button B: X+67, Y+21
+  Prize: X=12748, Y=12176
+
+  Button A: X+17, Y+86
+  Button B: X+84, Y+37
+  Prize: X=7870, Y=6450
+
+  Button A: X+69, Y+23
+  Button B: X+27, Y+71
+  Prize: X=18641, Y=10279`,
+        expected: 480,
+      },
+    ],
+    solution: part1,
+  },
+  part2: {
+    tests: [
+      // {
+      //   input: ``,
+      //   expected: "",
+      // },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+  onlyTests: false,
+})