day 4, messy

.aocrunner.json

@@ -47,16 +47,18 @@
     },
     {
       "part1": {
-        "solved": false,
-        "result": null,
-        "attempts": [],
-        "time": null
+        "solved": true,
+        "result": "2358",
+        "attempts": [
+          "0"
+        ],
+        "time": 327.70272
       },
       "part2": {
-        "solved": false,
-        "result": null,
+        "solved": true,
+        "result": "1737",
         "attempts": [],
-        "time": null
+        "time": 201.22507
       }
     },
     {

README.md

@@ -14,7 +14,7 @@
 [![Day](https://badgen.net/badge/01/%E2%98%85%E2%98%85/green)](src/day01)
 [![Day](https://badgen.net/badge/02/%E2%98%85%E2%98%85/green)](src/day02)
 [![Day](https://badgen.net/badge/03/%E2%98%85%E2%98%85/green)](src/day03)
-![Day](https://badgen.net/badge/04/%E2%98%86%E2%98%86/gray)
+[![Day](https://badgen.net/badge/04/%E2%98%85%E2%98%85/green)](src/day04)
 ![Day](https://badgen.net/badge/05/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/06/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/07/%E2%98%86%E2%98%86/gray)
@@ -83,16 +83,16 @@ Both parts: 3.539ms
 
 ```
 Day 03
-Time part 1: 0.657ms
-Time part 2: 0.406ms
-Both parts: 1.064ms
+Time part 1: 0.811ms
+Time part 2: 1.667ms
+Both parts: 2.477ms
 ```
 
 ```
 Day 04
-Time part 1: -
-Time part 2: -
-Both parts: -
+Time part 1: 327.703ms
+Time part 2: 201.225ms
+Both parts: 528.928ms
 ```
 
 ```
@@ -243,8 +243,8 @@ Both parts: -
 ```
 
 ```
-Total stars: 6/50
-Total time: 6.946ms
+Total stars: 8/50
+Total time: 537.288ms
 ```
 
 <!--/RESULTS-->

src/day04/README.md

@@ -0,0 +1,9 @@
+# 🎄 Advent of Code 2024 - day 4 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2024/day/4)
+
+## Notes
+
+...

src/day04/index.ts

@@ -0,0 +1,169 @@
+import run from "aocrunner"
+
+const parseInput = (rawInput: string) => {
+  return rawInput.split('\n').map(line => line.split(''))
+}
+
+const directions = ["down","right","dl","dr"] as const
+type Direction = typeof directions[number]
+type Prospect1 = {
+  letters: string
+  direction: Direction
+  next: [number, number]
+}
+type Coord = Prospect1['next']
+const getNext = (dir: Direction, [row, col]: Coord): Coord => {
+  switch(dir) {
+    case "down": {return [row+1, col]}
+    case "right": {return [row, col+1]}
+    case "dl": {return [row+1, col-1]}
+    case "dr": {return [row+1, col+1]}
+  }
+}
+
+const part1 = (rawInput: string) => {
+  const input = parseInput(rawInput)
+  let total = 0
+  let prospects: Prospect1[] = []
+  input.forEach((line, row) => {
+    line.forEach((letter, col) => {
+      prospects = prospects.map((prospect) => {
+        const {
+          direction,
+          letters,
+          next
+        } = prospect
+        if (next[0] < row) return null
+        if (next[0] === row && next[1] === col) {
+          const nextLetters = letters + letter
+          if (["XMAS","SAMX"].includes(nextLetters)) {
+            total += 1
+            return null
+          }
+          if (["XMA","SAM","XM","SA"].includes(nextLetters)) {
+            return {
+              letters: nextLetters,
+              direction: direction,
+              next: getNext(direction, next)
+            }
+          }
+        }
+        return prospect
+      }).filter(prospect => prospect != null)
+      if ("XMAS".includes(letter)) {
+        directions.forEach(direction => {
+          prospects.push({
+            letters: letter,
+            direction,
+            next: getNext(direction, [row, col])
+          })
+        })
+      }
+    })
+  })
+  return total
+}
+
+type Prospect2 = {
+  letters: string
+  direction: Direction
+  next: [number, number]
+  center: [number, number]
+}
+
+const part2 = (rawInput: string) => {
+  const input = parseInput(rawInput)
+  let centers = new Map<string, number>()
+  let prospects: Prospect2[] = []
+  let total = 0
+  input.forEach((line, row) => {
+    line.forEach((letter, col) => {
+      prospects = prospects.map((prospect) => {
+        const {
+          direction,
+          letters,
+          next
+        } = prospect
+        if (next[0] < row) return null
+        if (next[0] === row && next[1] === col) {
+          const nextLetters = letters + letter
+          if (["MAS","SAM"].includes(nextLetters)) {
+            const key = prospect.center.join(",")
+            if (centers.has(key)) { total++ }
+            centers.set(key, 1)
+            return null
+          }
+          if (["MA","SA"].includes(nextLetters)) {
+            return {
+              ...prospect,
+              letters: nextLetters,
+              next: getNext(direction, next),
+            }
+          }
+        }
+        return prospect
+      }).filter(prospect => prospect != null)
+      if ("XMAS".includes(letter)) {
+        ["dl" as const, "dr" as const].forEach(direction => {
+          const center = getNext(direction, [row, col])
+          prospects.push({
+            letters: letter,
+            direction,
+            next: center,
+            center,
+          })
+        })
+      }
+    })
+  })
+  return total
+}
+
+run({
+  part1: {
+    tests: [
+      {
+        input: `..X...
+.SAMX.
+.A..A.
+XMAS.S
+.X....`,
+        expected: 4
+      },
+      {
+        input: `MMMSXXMASM
+MSAMXMSMSA
+AMXSXMAAMM
+MSAMASMSMX
+XMASAMXAMM
+XXAMMXXAMA
+SMSMSASXSS
+SAXAMASAAA
+MAMMMXMMMM
+MXMXAXMASX`,
+        expected: 18,
+      },
+    ],
+    solution: part1,
+  },
+  part2: {
+    tests: [
+      {
+        input: `MMMSXXMASM
+MSAMXMSMSA
+AMXSXMAAMM
+MSAMASMSMX
+XMASAMXAMM
+XXAMMXXAMA
+SMSMSASXSS
+SAXAMASAAA
+MAMMMXMMMM
+MXMXAXMASX`,
+        expected: 9,
+      },
+    ],
+    solution: part2,
+  },
+  trimTestInputs: true,
+  onlyTests: false,
+})