Added 2022 day 8 solutions

TyShkan · Dec 8, 2022 · 5057c03 · 5057c03
1 parent 6337e3d
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diff --git a/2022/Sources/2022/Day8.swift b/2022/Sources/2022/Day8.swift
@@ -0,0 +1,109 @@
+import Algorithms
+import Collections
+import Foundation
+import RegexBuilder
+
+struct Point: Hashable {
+	var x: Int
+	var y: Int
+
+	func scenicScore(height: Int, in grid: [Point: Int], xSize: Int, ySize: Int) -> Int {
+		if x == 0 || y == 0 || y == ySize - 1 || x == xSize - 1 {
+			return 0
+		}
+
+		func visibility(for points: some Collection<Point>) -> Int {
+			var visibility = 0
+			for point in points {
+				visibility += 1
+				if grid[point]! >= height {
+					return visibility
+				}
+			}
+			return visibility
+		}
+
+		let left = visibility(for: (0 ..< x).reversed().map { Point(x: $0, y: y) })
+		let right = visibility(for: (x + 1 ..< xSize).map { Point(x: $0, y: y) })
+		let up = visibility(for: (0 ..< y).reversed().map { Point(x: x, y: $0) })
+		let down = visibility(for: (y + 1 ..< ySize).map { Point(x: x, y: $0) })
+		return left * right * up * down
+	}
+
+	func isVisible(height: Int, in grid: [Point: Int], xSize: Int, ySize: Int) -> Bool {
+		if x == 0 || y == 0 || y == ySize - 1 || x == xSize - 1 {
+			return true
+		}
+
+		if (0 ..< x).allSatisfy({ grid[Point(x: $0, y: y)]! < height }) {
+			return true
+		}
+
+		if (x + 1 ..< xSize).allSatisfy({ grid[Point(x: $0, y: y)]! < height }) {
+			return true
+		}
+
+		if (0 ..< y).allSatisfy({ grid[Point(x: x, y: $0)]! < height }) {
+			return true
+		}
+
+		if (y + 1 ..< ySize).allSatisfy({ grid[Point(x: x, y: $0)]! < height }) {
+			return true
+		}
+
+		return false
+	}
+}
+
+struct Day8: Day {
+	var input: String
+
+	init(input: String) {
+		self.input = input
+	}
+
+	func partOne() -> String {
+		let ySize = input.split(separator: "\n").count
+		let xSize = input.split(separator: "\n").first!.count
+
+		let trees = input
+			.split(separator: "\n")
+			.enumerated()
+			.reduce(into: [Point: Int]()) { dict, tuple in
+				let (y, line) = tuple
+				line.enumerated().forEach { x, c in
+					dict[Point(x: x, y: y)] = c.wholeNumberValue!
+				}
+			}
+
+		return trees
+			.lazy
+			.filter { point, height in
+				point.isVisible(height: height, in: trees, xSize: xSize, ySize: ySize)
+			}
+			.count
+			.description
+	}
+
+	func partTwo() -> String {
+		let ySize = input.split(separator: "\n").count
+		let xSize = input.split(separator: "\n").first!.count
+
+		let trees = input
+			.split(separator: "\n")
+			.enumerated()
+			.reduce(into: [Point: Int]()) { dict, tuple in
+				let (y, line) = tuple
+				line.enumerated().forEach { x, c in
+					dict[Point(x: x, y: y)] = c.wholeNumberValue!
+				}
+			}
+		return trees
+			.lazy
+			.map { point, height in
+				point.scenicScore(height: height, in: trees, xSize: xSize, ySize: ySize)
+			}
+			.max()!
+			.description
+	}
+}
diff --git a/2022/Sources/2022/main.swift b/2022/Sources/2022/main.swift
@@ -1,6 +1,6 @@
 import Foundation
 
-typealias CurrentDay = Day7
+typealias CurrentDay = Day8
 
 let testInput = """
 <Insert your test input here>