05a

Sources/aoc2021/05.swift

@@ -0,0 +1,95 @@
+//
+//  File.swift
+//  
+//
+//  Created by Max Nuding on 05.12.21.
+//
+
+import Foundation
+
+struct Line: CustomStringConvertible {
+    let from: Point
+    let to: Point
+    
+    var description: String { "\(from.x),\(from.y) -> \(to.x),\(to.y)" }
+    var isStraight: Bool { from.x == to.x || from.y == to.y }
+    
+    init(inputLine: String) {
+        let points = inputLine.components(separatedBy: " -> ")
+        let res = points.map { point in point.split(separator: ",").map { Int($0)! } }
+        from = Point(x: res[0][0], y: res[0][1])
+        to = Point(x: res[1][0], y: res[1][1])
+    }
+    
+    func getCoveredPoints() -> [Point] {
+        guard isStraight else {
+            return [Point]()
+        }
+        
+        var points = [Point]()
+        let startX = min(from.x, to.x)
+        let endX = max(from.x, to.x)
+        let startY = min(from.y, to.y)
+        let endY = max(from.y, to.y)
+        
+        for x in startX...endX {
+            for y in startY...endY {
+                points.append(Point(x: x, y: y))
+            }
+        }
+        return points
+    }
+}
+
+struct Point: Hashable {
+    let x: Int
+    let y: Int
+}
+
+struct Field: CustomStringConvertible {
+    var coveredPoints = [Point: Int]()
+    
+    var description: String {
+        let minX = coveredPoints.min(by: {$0.key.x < $1.key.x})?.key.x ?? 0
+        let minY = coveredPoints.min(by: {$0.key.y < $1.key.y})?.key.y ?? 0
+        let maxX = coveredPoints.max(by: {$0.key.x < $1.key.x})?.key.x ?? 0
+        let maxY = coveredPoints.max(by: {$0.key.y < $1.key.y})?.key.y ?? 0
+        var desc = "Field from \(minX), \(minY) to \(maxX), \(maxY))\n"
+        for y in minY...maxY {
+            for x in minX...maxX {
+                let val = coveredPoints[Point(x: x, y: y)] ?? 0
+                desc += val == 0 ? "." : "\(val)"
+            }
+            desc += "\n"
+        }
+        return desc
+    }
+    
+    mutating func cover(point: Point) {
+        coveredPoints[point] = (coveredPoints[point] ?? 0) + 1
+    }
+}
+
+struct Day05 {
+    let inputPath: String
+    
+    func run() {
+        let input = try! String(contentsOfFile: inputPath)
+        let lines = input
+            .components(separatedBy: .newlines)
+            .filter { !$0.isEmpty }
+            .compactMap { Line(inputLine: $0) }
+        run(lines: lines.filter { $0.isStraight })
+    }
+    func run(lines: [Line]) {
+        var field = Field()
+        //let straightLines = lines.filter { $0.isStraight }
+        for line in lines {
+            for point in line.getCoveredPoints() {
+                field.cover(point: point)
+            }
+        }
+        print(field)
+        print(field.coveredPoints.filter { $0.value > 1}.count)
+    }
+}

Sources/aoc2021/main.swift

@@ -30,6 +30,7 @@ let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
 print("Finished in \(execTimeMs)ms")
 */
 
+/*
 print("Starting day 04")
 let input03 = Bundle.module.path(forResource: "04", ofType: ".txt")!
 let start = CFAbsoluteTimeGetCurrent()
@@ -37,3 +38,13 @@ Day04(inputPath: input03).run()
 let end = CFAbsoluteTimeGetCurrent()
 let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
 print("Finished in \(execTimeMs)ms")
+*/
+
+print("Starting day 05")
+let input03 = Bundle.module.path(forResource: "05_test", ofType: ".txt")!
+let start = CFAbsoluteTimeGetCurrent()
+Day05(inputPath: input03).run()
+let end = CFAbsoluteTimeGetCurrent()
+let execTimeMs = round((end - start) * 1000.0 * 100.0) / 100.0
+print("Finished in \(execTimeMs)ms")
+