03a

.gitignore

@@ -1,3 +1,4 @@
+.swiftpm/
 .DS_Store
 /.build
 /Packages

Package.resolved

@@ -1,16 +0,0 @@
-{
-  "object": {
-    "pins": [
-      {
-        "package": "swift-collections",
-        "repositoryURL": "https://github.com/apple/swift-collections.git",
-        "state": {
-          "branch": null,
-          "revision": "48254824bb4248676bf7ce56014ff57b142b77eb",
-          "version": "1.0.2"
-        }
-      }
-    ]
-  },
-  "version": 1
-}

Package.swift

@@ -5,13 +5,14 @@ import PackageDescription
 
 let package = Package(
     name: "aoc2021",
+    platforms: [.macOS(.v12)],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
         // .package(url: /* package url */, from: "1.0.0"),
-        .package(
+        /*.package(
               url: "https://github.com/apple/swift-collections.git",
               .upToNextMajor(from: "1.0.0")
-        )
+        )*/
     ],
     targets: [
         // Targets are the basic building blocks of a package. A target can define a module or a test suite.
@@ -19,7 +20,7 @@ let package = Package(
         .executableTarget(
             name: "aoc2021",
             dependencies: [
-                .product(name: "Collections", package: "swift-collections")
+                //.product(name: "Collections", package: "swift-collections")
             ],
             resources: [
                 .process("Resources"),

Sources/aoc2021/03.swift

@@ -0,0 +1,64 @@
+//
+//  File.swift
+//
+//
+//  Created by Max Nuding on 02.12.21.
+//
+
+import Foundation
+import AppKit
+
+struct Day03 {
+    let inputPath: String
+    
+    func run() {
+        let input = try! String(contentsOfFile: inputPath)
+        let commands = input
+            .components(separatedBy: .newlines)
+            .filter { !$0.isEmpty }
+            //.compactMap { MoveCommand(line: $0) }
+        runA(commands)
+        //runB(commands)
+    }
+    
+    func runA(_ commands: [String]) {
+        let neededForMajority = commands.count / 2
+        let lastBitIndex = commands.first!.count
+        var countsOnes = [Int](repeating: 0, count: lastBitIndex)
+        for command in commands {
+            let m = command.map { Bool.init(digit: $0)! }.map { $0 ? 1 : 0 }
+            countsOnes.enumerated().forEach { (idx, elem) in
+                countsOnes[idx] += m[idx]
+            }
+        }
+        let dec = countsOnes.indices.reduce((gamma: 0, episolon: 0), { partialResult, idx in
+            let isOne = countsOnes[idx] > neededForMajority
+            let val = Int(truncating: NSDecimalNumber(decimal: pow(2, countsOnes.count - idx - 1)))
+            var (gamma, episolon) = partialResult
+            if isOne {
+                gamma += val
+            } else {
+                episolon += val
+            }
+            return (gamma, episolon)
+        })
+        print(dec.episolon * dec.gamma)<
+    }
+    
+    func runB(_ commands: [String]) {
+        
+    }
+}
+
+extension Bool {
+    init?(digit: Character) {
+        switch digit {
+        case "0":
+            self = false
+        case "1":
+            self = true
+        default:
+            return nil
+        }
+    }
+}

Sources/aoc2021/main.swift

@@ -1,5 +1,5 @@
 import Foundation
-
+//import Collections
 /*
 print("Starting day 01")
 let input01 = Bundle.module.path(forResource: "01", ofType: ".txt")!
@@ -10,6 +10,7 @@ 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()
@@ -17,3 +18,12 @@ Day02(inputPath: input02).run()
 let end = CFAbsoluteTimeGetCurrent()
 let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
 print("Finished in \(execTimeMs)ms")
+*/
+
+print("Starting day 03")
+let input03 = Bundle.module.path(forResource: "03", ofType: ".txt")!
+let start = CFAbsoluteTimeGetCurrent()
+Day03(inputPath: input03).run()
+let end = CFAbsoluteTimeGetCurrent()
+let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
+print("Finished in \(execTimeMs)ms")