day5 1

Author: spaenleh

README.md

@@ -11,8 +11,8 @@ Below is my current advancement in Advent of code:
 | Day 1 | :star: | :star: |
 | Day 2 | :star: | :star: |
 | Day 3 | :star: | :star: |
-| Day 4 |  |  |
-| Day 5 |  |  |
+| Day 4 | :star: | :star: |
+| Day 5 | :star: (22min) |  |
 | Day 6 |  |  |
 | Day 7 |  |  |
 | Day 8 |  |  |

Sources/AdventOfCode.swift

@@ -6,6 +6,7 @@ let allChallenges: [any AdventDay] = [
   Day02(),
   Day03(),
   Day04(),
+  Day05(),
 ]
 
 @main

Sources/Day04.swift

@@ -1,71 +1,71 @@
 import Algorithms
 
 func searchInNeighbors(pos: Coord, _ grid: Grid) -> [Coord] {
-    pos.fullNeighbors.included(in: grid).filter { n in
-        grid[n] == "M"
-    }
+  pos.fullNeighbors.included(in: grid).filter { n in
+    grid[n] == "M"
+  }
 }
 
 func isMAS(pos: Coord, _ grid: Grid) -> Bool {
-    let candidates = pos.cornerNeighbors
-    if (candidates.allSatisfy { $0.isInside(grid: grid) }) {
-        let l = candidates.map { grid[$0] }
-        let letterSet = Set(l)
-        // same letter can not be on opposite side
-        return l[0] != l[2] && l[1] != l[3] && letterSet.count == 2 && letterSet == ["M", "S"]
-    }
-    return false
+  let candidates = pos.cornerNeighbors
+  if (candidates.allSatisfy { $0.isInside(grid: grid) }) {
+    let l = candidates.map { grid[$0] }
+    let letterSet = Set(l)
+    // same letter can not be on opposite side
+    return l[0] != l[2] && l[1] != l[3] && letterSet.count == 2 && letterSet == ["M", "S"]
+  }
+  return false
 }
 
 func isWhole(pos: Coord, inDir: Coord, grid: Grid) -> Bool {
-    let aPos = pos + inDir
-    let sPos = aPos + inDir
-    if aPos.isInside(grid: grid) && sPos.isInside(grid: grid) {
-        return grid[aPos] == "A" && grid[sPos] == "S"
-    }
-    return false
+  let aPos = pos + inDir
+  let sPos = aPos + inDir
+  if aPos.isInside(grid: grid) && sPos.isInside(grid: grid) {
+    return grid[aPos] == "A" && grid[sPos] == "S"
+  }
+  return false
 }
 
 struct Day04: AdventDay {
-    var grid: Grid
-    init(data: String) {
-        grid = Grid(from: data)
-    }
-    
-    func countAllWhere(letter search: Character, predicate: (Coord, Grid) -> Bool) -> Int {
-        grid.raw.enumerated().map { (y, line) in
-            line.enumerated().map { (x, letter) in
-                if letter == search {
-                    return predicate(Coord(x: x, y: y), grid)
-                }
-                return false
-            }
-        }.flatMap { $0 }.count { $0 == true }
-    }
-    
-    func part1() -> Int {
-        var count = 0
-        // get all positions of "X"
-        for (y, line) in grid.raw.enumerated() {
-            for (x, letter) in line.enumerated() {
-                if letter == "X" {
-                    let currentPos = Coord(x: x, y: y)
-                    let results = searchInNeighbors(pos: currentPos, grid)
-                    if results.count > 0 {
-                        for candidate in results {
-                            let inDir = candidate - currentPos
-                            if isWhole(pos: candidate, inDir: inDir, grid: grid) {
-                                count += 1
-                            }
-                        }
-                    }
-                }
+  var grid: Grid
+  init(data: String) {
+    grid = Grid(from: data)
+  }
+
+  func countAllWhere(letter search: Character, predicate: (Coord, Grid) -> Bool) -> Int {
+    grid.raw.enumerated().map { (y, line) in
+      line.enumerated().map { (x, letter) in
+        if letter == search {
+          return predicate(Coord(x: x, y: y), grid)
+        }
+        return false
+      }
+    }.flatMap { $0 }.count { $0 == true }
+  }
+
+  func part1() -> Int {
+    var count = 0
+    // get all positions of "X"
+    for (y, line) in grid.raw.enumerated() {
+      for (x, letter) in line.enumerated() {
+        if letter == "X" {
+          let currentPos = Coord(x: x, y: y)
+          let results = searchInNeighbors(pos: currentPos, grid)
+          if results.count > 0 {
+            for candidate in results {
+              let inDir = candidate - currentPos
+              if isWhole(pos: candidate, inDir: inDir, grid: grid) {
+                count += 1
+              }
             }
+          }
         }
-        return count
-    }
-    
-    func part2() -> Int {
-        countAllWhere(letter: "A", predicate: isMAS)
+      }
     }
+    return count
+  }
+
+  func part2() -> Int {
+    countAllWhere(letter: "A", predicate: isMAS)
+  }
 }

Sources/Day05.swift

@@ -0,0 +1,50 @@
+import Algorithms
+
+struct Rule {
+  var before: Int
+  var after: Int
+
+}
+extension Rule {
+  init(data: Substring) {
+    let parts = data.split(separator: "|")
+    before = Int(parts[0]) ?? 0
+    after = Int(parts[1]) ?? 0
+  }
+}
+
+struct Day05: AdventDay {
+  var rules: [Int: [Int]]
+  var updates: [[Int]]
+
+  init(data: String) {
+    let parts = data.split(separator: "\n\n")
+    rules = [Int: [Int]]()
+    for line in parts[0].lines() {
+      let parts = line.split(separator: "|")
+      let before = Int(parts[0]) ?? 0
+      let after = Int(parts[1]) ?? 0
+      rules[after, default: [Int]()].append(before)
+    }
+    updates = parts[1].lines().map { $0.integers(separator: ",") }
+  }
+
+  func part1() -> Int {
+    updates.filter { update in
+      for (idx, page) in update.enumerated() {
+        let rulesForPage = rules[page, default: [Int]()]
+        let brokenRules = rulesForPage.map { update[idx + 1..<update.count].contains($0) }.count {
+          $0 == true
+        }
+        if brokenRules > 0 {
+          return false
+        }
+      }
+      return true
+    }.map { update in update[update.count / 2] }.sum
+  }
+
+  func part2() -> Int {
+    0
+  }
+}

Sources/Helpers/Grid.swift

@@ -25,12 +25,13 @@ extension Grid {
   init(from data: String) {
     self.raw = data.lines().map { Array($0) }
   }
-    
-    func toText() -> String {
-        String(self.raw.map {
-            String($0)
-        }.joined(by: "\n"))
-    }
+
+  func toText() -> String {
+    String(
+      self.raw.map {
+        String($0)
+      }.joined(by: "\n"))
+  }
 
   func includes(coord: Coord) -> Bool {
     coord.x >= 0 && coord.x <= self.width - 1 && coord.y >= 0 && coord.y <= self.height - 1

Tests/Day05.swift

@@ -0,0 +1,55 @@
+import Testing
+
+@testable import aoc
+
+@Suite("Day05")
+struct Day05Tests {
+  let testData = """
+    47|53
+    97|13
+    97|61
+    97|47
+    75|29
+    61|13
+    75|53
+    29|13
+    97|29
+    53|29
+    61|53
+    97|53
+    61|29
+    47|13
+    75|47
+    97|75
+    47|61
+    75|61
+    47|29
+    75|13
+    53|13
+
+    75,47,61,53,29
+    97,61,53,29,13
+    75,29,13
+    75,97,47,61,53
+    61,13,29
+    97,13,75,29,47
+    """
+
+  @Test("parsing")
+  func testParsing() async throws {
+    let challenge = Day05(data: testData)
+    #expect(challenge.updates.count == 6)
+  }
+
+  @Test("part1")
+  func testPart1() async throws {
+    let challenge = Day05(data: testData)
+    #expect(challenge.part1() == 143)
+  }
+
+  @Test("part2")
+  func testPart2() async throws {
+    let challenge = Day05(data: testData)
+    #expect(challenge.part2() == 0)
+  }
+}