day 4

src/day04/README.md

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+# 🎄 Advent of Code 2023 - day 4 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2023/day/4)
+
+## Notes
+
+...

src/day04/index.ts

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+import run from "aocrunner"
+
+const parseInput = (rawInput: string) =>
+  rawInput.split("\n").map((line) => {
+    const [, b] = line.split(/:\s+/)
+    return b.split(" | ").map((x) => x.split(/\s+/).map(Number)) as [
+      number[],
+      number[],
+    ]
+  })
+
+const part1 = (rawInput: string) => {
+  const input = parseInput(rawInput)
+  return input.reduce((total, [winning, have]) => {
+    const numMatches = have.filter((x) => winning.includes(x)).length
+    if (numMatches === 0) {
+      return total
+    }
+    return total + 2 ** (numMatches - 1)
+  }, 0)
+}
+
+const part2 = (rawInput: string) => {
+  const input = parseInput(rawInput)
+  const counts = input.map((x) => 1)
+  input.forEach(([winning, have], row) => {
+    const numMatches = have.filter((x) => winning.includes(x)).length
+    for (let i = 0; i < numMatches; i++) {
+      counts[row + i + 1] += counts[row]
+    }
+  }, 0)
+  return counts.reduce((total, x) => total + x)
+}
+
+run({
+  part1: {
+    tests: [
+      {
+        input: `Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11`,
+        expected: 13,
+      },
+    ],
+    solution: part1,
+  },
+  part2: {
+    tests: [
+      {
+        input: `Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11`,
+        expected: 30,
+      },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+  onlyTests: false,
+})