17a+b

Package.swift

@@ -25,7 +25,8 @@ let package = Package(
             .executable(name: "13", targets: ["13"]),
             .executable(name: "14", targets: ["14"]),
             .executable(name: "15", targets: ["15"]),
-            .executable(name: "16", targets: ["16"])
+            .executable(name: "16", targets: ["16"]),
+            .executable(name: "17", targets: ["17"])
         ],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
@@ -121,6 +122,10 @@ let package = Package(
         ),
         .executableTarget(
             name: "16",
+            dependencies: [ .targetItem(name: "Runner", condition: nil) ]
+        ),
+        .executableTarget(
+            name: "17",
             dependencies: [ .targetItem(name: "Runner", condition: nil),
                             .product(name: "Collections", package: "swift-collections")]
         )

Sources/16/16.swift

@@ -7,7 +7,6 @@
 
 import Foundation
 import Runner
-import Collections
 
 
 enum OperatorType: Int {

Sources/17/17.swift

@@ -0,0 +1,107 @@
+//
+//  File.swift
+//
+//
+//  Created by Max Nuding on 17.12.21.
+//
+
+import Foundation
+import Runner
+import Collections
+
+struct Point:Hashable {
+    let x: Int
+    let y: Int
+}
+
+struct Area {
+    let topLeft: Point
+    let botRight: Point
+    
+    init(x: String, y: String) {
+        let xVals = x[x.index(x.startIndex, offsetBy: 2)...].components(separatedBy: "..").map { Int($0)! }
+        let yVals = y[y.index(y.startIndex, offsetBy: 2)...].components(separatedBy: "..").map { Int($0)! }
+        topLeft = Point(x: xVals.first!, y: yVals.last!)
+        botRight = Point(x: xVals.last!, y: yVals.first!)
+    }
+    
+    func contains(point: Point) -> Bool {
+        point.x >= topLeft.x && point.x <= botRight.x && point.y <= topLeft.y && point.y >= botRight.y
+    }
+    
+    func overshot(point: Point) -> Bool {
+        overshotX(point: point) || overshotY(point: point)
+    }
+    
+    func overshotX(point: Point) -> Bool {
+        point.x > botRight.x
+    }
+    
+    func overshotY(point: Point) -> Bool {
+        point.y < botRight.y
+    }
+}
+
+struct Probe {
+    var position: Point
+    var velocity: Point
+    
+    mutating func move() {
+        position = Point(x: position.x + velocity.x, y: position.y + velocity.y)
+        var dX: Int
+        switch velocity.x {
+        case _ where velocity.x < 0:
+            dX = 1
+        case 0:
+            dX = 0
+        case _ where velocity.x > 0:
+            dX = -1
+        default:
+            fatalError()
+        }
+        velocity = Point(x: velocity.x + dX, y: velocity.y - 1)
+        
+    }
+}
+
+class Day17: Runnable {
+    let inputPath: String
+    
+    required init(inputPath: String) {
+        self.inputPath = inputPath
+    }
+    
+    public func run() {
+        let input = try! String(contentsOfFile: inputPath)
+        let parts = input
+            .trimmingCharacters(in: .newlines)
+            .components(separatedBy: ": ")
+            .last!
+            .components(separatedBy: ", ")
+        let area = Area(x: parts.first!, y: parts.last!)
+        
+        var maxY = Int.min
+        var found = Set<Point>()
+        for x in -500...500 {
+            for y in -500...500 {
+                let velocity = Point(x: x, y: y)
+                var probe = Probe(position: Point(x: 0, y: 0), velocity: velocity)
+                var maxYCurrent = Int.min
+                while !area.contains(point: probe.position) && !area.overshot(point: probe.position) {
+                    probe.move()
+                    if probe.position.y > maxYCurrent {
+                        maxYCurrent = probe.position.y
+                    }
+                }
+                if area.contains(point: probe.position) {
+                    if maxYCurrent > maxY {
+                        maxY = maxYCurrent
+                    }
+                    found.insert(velocity)
+                }
+            }
+        }
+        print(maxY)
+        print(found.count)
+    }
+}

Sources/17/main.swift

@@ -0,0 +1,12 @@
+//
+//  File.swift
+//  
+//
+//  Created by Max Nuding on 17.12.21.
+//
+
+import Foundation
+import Runner
+
+//Runner(target: Day17.self, day: "17", isTest: true).run()
+Runner(target: Day17.self, day: "17", isTest: false).run()

Sources/Runner/Resources/input/17.txt

@@ -0,0 +1 @@
+target area: x=128..160, y=-142..-88

Sources/Runner/Resources/input/17_test.txt

@@ -0,0 +1 @@
+target area: x=20..30, y=-10..-5