12a

Sources/12/12.swift

@@ -0,0 +1,111 @@
+//
+//  File.swift
+//
+//
+//  Created by Max Nuding on 12.12.21.
+//
+
+import Foundation
+import Runner
+import Collections
+
+class Cave: Hashable, CustomStringConvertible, CustomDebugStringConvertible {
+    static func == (lhs: Cave, rhs: Cave) -> Bool { lhs.name == rhs.name }
+    
+    func hash(into hasher: inout Hasher) {
+        hasher.combine(name)
+    }
+    
+    var description: String { name }
+    var debugDescription: String { name }
+    
+    let name: String
+    var connectedCaves = [Cave]()
+    var isBigCave: Bool
+    var isEnd: Bool
+    
+    required init(name: String) {
+        self.name = name
+        self.isBigCave = name.first!.isUppercase
+        self.isEnd = name == "end"
+    }
+}
+
+class Path: Hashable, CustomStringConvertible {
+    static func == (lhs: Path, rhs: Path) -> Bool {
+        lhs.parts == rhs.parts
+    }
+    
+    func hash(into hasher: inout Hasher) {
+        hasher.combine(parts)
+    }
+    
+    var parts: [Cave]
+    private var partsSet: Set<Cave>
+    var description: String { parts.map {$0.description}.joined(separator: "->") }
+    
+    required init(parts: [Cave]) {
+        self.parts = parts
+        partsSet = Set(parts)
+    }
+    
+    func contains(cave: Cave) -> Bool { partsSet.contains(cave) }
+}
+
+class Day12: Runnable {
+    let inputPath: String
+    var caves = [String:Cave]()
+    
+    required init(inputPath: String) {
+        self.inputPath = inputPath
+    }
+    
+    public func run() {
+        let input = try! String(contentsOfFile: inputPath)
+        caves = input
+            .trimmingCharacters(in: .newlines)
+            .components(separatedBy: .newlines)
+            .reduce(into: [String:Cave](), { caves, line in
+                let caveConnection = line.components(separatedBy: "-")
+                let caveFromName = caveConnection.first!
+                let caveToName = caveConnection.last!
+                let from = caves[caveFromName] ?? Cave(name: caveFromName)
+                let to = caves[caveToName] ?? Cave(name: caveToName)
+                from.connectedCaves.append(to)
+                to.connectedCaves.append(from)
+                caves[caveFromName] = from
+                caves[caveToName] = to
+                
+            })
+        
+        var queue = Deque<Path>(minimumCapacity: 10000)
+        var visited = Set<Path>(minimumCapacity: 10000)
+        var numFinished = 0
+        
+        var cave: Path? = Path(parts: [caves["start"]!])
+        queue.append(cave!)
+        
+        while !queue.isEmpty {
+            cave = queue.popFirst()
+            if visited.contains(cave!) {
+                continue
+            }
+            //print("Current path: \(cave!)")
+            visited.insert(cave!)
+            
+            cave!.parts.last!.connectedCaves
+                .filter { $0.isBigCave || !cave!.contains(cave: $0) }
+                .forEach {
+                    if $0.isEnd {
+                        numFinished += 1
+                        //print("Finished: \(cave!.parts)->end")
+                        return
+                    }
+                    var newParts = cave!.parts
+                    newParts.append($0)
+                    queue.append(Path(parts: newParts))
+                }
+        }
+        print(numFinished)
+    }
+}

Sources/12/main.swift

@@ -0,0 +1,12 @@
+//
+//  File.swift
+//  
+//
+//  Created by Max Nuding on 05.12.21.
+//
+
+import Foundation
+import Runner
+
+//Runner(target: Day12.self, day: "12", isTest: true).run()
+Runner(target: Day12.self, day: "12", isTest: false).run()