02

Sources/aoc2021/02.swift

@@ -0,0 +1,89 @@
+//
+//  File.swift
+//  
+//
+//  Created by Max Nuding on 02.12.21.
+//
+
+import Foundation
+
+enum Direction: String {
+    case forward
+    case down
+    case up
+    init?(rawValue: String) {
+        switch rawValue {
+        case "forward":
+            self = .forward
+        case "down":
+            self = .down
+        case "up":
+            self = .up
+        default:
+            return nil
+        }
+    }
+}
+
+struct MoveCommand {
+    let direction: Direction
+    let amount: Int
+    
+    init?(line: String) {
+        guard !line.isEmpty else {
+            return nil
+        }
+        let parts = line.components(separatedBy: .whitespaces)
+        direction = Direction(rawValue: parts[0])!
+        amount = Int(parts[1])!
+    }
+}
+
+struct Day02 {
+    let inputPath: String
+    
+    
+    func run() {
+        let input = try! String(contentsOfFile: inputPath)
+        let commands = input
+            .components(separatedBy: .newlines)
+            .compactMap { MoveCommand(line: $0) }
+        runA(commands: commands)
+        runB(commands: commands)
+    }
+    
+    func runA(commands: [MoveCommand]) {
+        var horizontalPos = 0
+        var depth = 0
+        for command in commands {
+            switch command.direction {
+            case .forward:
+                horizontalPos += command.amount
+            case .up:
+                depth -= command.amount
+            case .down:
+                depth += command.amount
+            }
+        }
+        print(horizontalPos * depth)
+    }
+    
+    func runB(commands: [MoveCommand]) {
+        var horizontalPos = 0
+        var depth = 0
+        var aim = 0
+        for command in commands {
+            switch command.direction {
+            case .forward:
+                horizontalPos += command.amount
+                depth += aim * command.amount
+            case .up:
+                aim -= command.amount
+            case .down:
+                aim += command.amount
+            }
+        }
+        print(horizontalPos * depth)
+    }
+}
+

Sources/aoc2021/main.swift

@@ -1,5 +1,6 @@
 import Foundation
 
+/*
 print("Starting day 01")
 let input01 = Bundle.module.path(forResource: "01", ofType: ".txt")!
 let start = CFAbsoluteTimeGetCurrent()
@@ -7,3 +8,12 @@ Day01(inputPath: input01).run()
 let end = CFAbsoluteTimeGetCurrent()
 let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
 print("Finished in \(execTimeMs)ms")
+*/
+
+print("Starting day 02")
+let input02 = Bundle.module.path(forResource: "02", ofType: ".txt")!
+let start = CFAbsoluteTimeGetCurrent()
+Day02(inputPath: input02).run()
+let end = CFAbsoluteTimeGetCurrent()
+let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
+print("Finished in \(execTimeMs)ms")