day 5

src/day05/README.md

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+# 🎄 Advent of Code 2021 - day 5 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2021/day/5)
+
+## Notes
+
+...

src/day05/index.js

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+import run from "aocrunner"
+import { sequence } from "../utils/index.js"
+
+const parseInput = (rawInput) =>
+  rawInput.split`\n`.map((l) => l.split(/ -> |,/).map((x) => +x))
+
+const part1 = (rawInput) => {
+  const input = parseInput(rawInput)
+  const visited = new Map()
+  input.forEach(([ax, ay, bx, by]) => {
+    const dx = Math.sign(bx - ax)
+    const dy = Math.sign(by - ay)
+    if (dx == 0 || dy == 0) {
+      for (let x = ax, y = ay; x != bx + dx || y != by + dy; x += dx, y += dy) {
+        const key = `${x},${y}`
+        const value = visited.get(key) || 0
+        visited.set(key, value + 1)
+      }
+    }
+  })
+
+  return [...visited.values()].filter((x) => x > 1).length
+}
+
+const part2 = (rawInput) => {
+  const input = parseInput(rawInput)
+  const visited = new Map()
+  input.forEach(([ax, ay, bx, by]) => {
+    const dx = Math.sign(bx - ax)
+    const dy = Math.sign(by - ay)
+    for (let x = ax, y = ay; x != bx + dx || y != by + dy; x += dx, y += dy) {
+      const key = `${x},${y}`
+      const value = visited.get(key) || 0
+      visited.set(key, value + 1)
+    }
+  })
+
+  return [...visited.values()].filter((x) => x > 1).length
+}
+
+run({
+  part1: {
+    tests: [
+      {
+        input: `0,9 -> 5,9
+8,0 -> 0,8
+9,4 -> 3,4
+2,2 -> 2,1
+7,0 -> 7,4
+6,4 -> 2,0
+0,9 -> 2,9
+3,4 -> 1,4
+0,0 -> 8,8
+5,5 -> 8,2`,
+        expected: 5,
+      },
+    ],
+    solution: part1,
+  },
+  part2: {
+    tests: [
+      // { input: ``, expected: "" },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+})