day 13

.aocrunner.json

@@ -181,16 +181,16 @@
     },
     {
       "part1": {
-        "solved": false,
-        "result": null,
+        "solved": true,
+        "result": "847",
         "attempts": [],
-        "time": null
+        "time": 3.59
       },
       "part2": {
-        "solved": false,
-        "result": null,
+        "solved": true,
+        "result": "BCZRCEAB",
         "attempts": [],
-        "time": null
+        "time": 17.85
       }
     },
     {

README.md

@@ -23,7 +23,7 @@
 [![Day](https://badgen.net/badge/10/%E2%98%85%E2%98%85/green)](src/day10)
 [![Day](https://badgen.net/badge/11/%E2%98%85%E2%98%85/green)](src/day11)
 [![Day](https://badgen.net/badge/12/%E2%98%85%E2%98%85/green)](src/day12)
-![Day](https://badgen.net/badge/13/%E2%98%86%E2%98%86/gray)
+[![Day](https://badgen.net/badge/13/%E2%98%85%E2%98%86/green)](src/day13)
 ![Day](https://badgen.net/badge/14/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/15/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/16/%E2%98%86%E2%98%86/gray)
@@ -153,9 +153,9 @@ Both parts: 602.51ms
 
 ```
 Day 13
-Time part 1: -
+Time part 1: 3.8ms
 Time part 2: -
-Both parts: -
+Both parts: 3.8ms
 ```
 
 ```
@@ -243,8 +243,8 @@ Both parts: -
 ```
 
 ```
-Total stars: 24/50
-Total time: 1056.76ms
+Total stars: 25/50
+Total time: 1060.56ms
 ```
 
 <!--/RESULTS-->

src/day13/README.md

@@ -0,0 +1,9 @@
+# 🎄 Advent of Code 2021 - day 13 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2021/day/13)
+
+## Notes
+
+...

src/day13/index.js

@@ -0,0 +1,92 @@
+import run from "aocrunner"
+
+const parseInput = (rawInput) => {
+  const [Sdots, Sfolds] = rawInput.trim().split`\n\n`
+  return [
+    new Set(Sdots.split`\n`),
+    Sfolds.split`\n`.map((x) => x.split(/[ =]/).splice(2)),
+  ]
+}
+
+function fold(dots, n, axis) {
+  n = +n
+  const nextSet = new Set()
+  dots.forEach((dot) => {
+    const [x, y] = dot.split`,`.map((x) => +x)
+    if (axis == "x") {
+      nextSet.add(x <= n ? dot : `${2 * n - x},${y}`)
+    } else {
+      nextSet.add(y <= n ? dot : `${x},${2 * n - y}`)
+    }
+  })
+  return nextSet
+}
+
+const part1 = (rawInput) => {
+  const [dots, folds] = parseInput(rawInput)
+  let currentDots = dots
+  folds.slice(0, 1).forEach(([axis, n]) => {
+    currentDots = fold(currentDots, n, axis)
+  })
+  return currentDots.size
+}
+
+const part2 = (rawInput) => {
+  const [dots, folds] = parseInput(rawInput)
+  let currentDots = dots
+  folds.forEach(([axis, n]) => {
+    currentDots = fold(currentDots, n, axis)
+  })
+  const field = [...currentDots].map((d) => d.split`,`.map((x) => +x))
+  const [maxX, maxY] = field.reduce(
+    ([maxX, maxY], [x, y]) => [Math.max(x, maxX), Math.max(y, maxY)],
+    [0, 0],
+  )
+  for (let y = 0; y <= maxY; y++) {
+    let line = ""
+    for (let x = 0; x <= maxX; x++) {
+      line += currentDots.has(`${x},${y}`) ? "█" : " "
+    }
+    console.log(line)
+  }
+  return
+}
+
+run({
+  part1: {
+    tests: [
+      {
+        input: `6,10
+0,14
+9,10
+0,3
+10,4
+4,11
+6,0
+6,12
+4,1
+0,13
+10,12
+3,4
+3,0
+8,4
+1,10
+2,14
+8,10
+9,0
+
+fold along y=7
+fold along x=5`,
+        expected: 17,
+      },
+    ],
+    solution: part1,
+  },
+  part2: {
+    tests: [
+      // { input: ``, expected: "" },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+})