Added 2022 day 14 solutions

HarshilShah · Dec 14, 2022 · 2372860 · 2372860
1 parent b5b747b
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diff --git a/2022/Sources/2022/Day14.swift b/2022/Sources/2022/Day14.swift
@@ -0,0 +1,167 @@
+import Algorithms
+import Collections
+import Foundation
+import RegexBuilder
+
+extension StringProtocol {
+	var integers: [Int] {
+		return self
+			.split{ "0123456789".contains($0) == false }
+			.map { Int($0)! }
+	}
+}
+
+extension Sequence {
+	func min<T: Comparable>(_ keyPath: KeyPath<Element, T>) -> T? {
+		return self.min(by: { $0[keyPath: keyPath] < $1[keyPath: keyPath] })?[keyPath: keyPath]
+	}
+
+	func max<T: Comparable>(_ keyPath: KeyPath<Element, T>) -> T? {
+		return self.max(by: { $0[keyPath: keyPath] < $1[keyPath: keyPath] })?[keyPath: keyPath]
+	}
+
+	func range<T: Comparable>(_ keyPath: KeyPath<Element, T>) -> ClosedRange<T>? {
+		guard let minimum = min(keyPath), let maximum = max(keyPath) else {
+			return nil
+		}
+
+		return minimum...maximum
+	}
+}
+
+fileprivate struct Point: Hashable {
+	var x: Int
+	var y: Int
+}
+
+fileprivate enum Tile: Hashable {
+	case rock
+	case sand
+
+	var description: String {
+		switch self {
+		case .rock: return "#"
+		case .sand: return "o"
+		}
+	}
+}
+
+struct Day14: Day {
+	var input: String
+
+	init(input: String) {
+		self.input = input
+	}
+
+	func partOne() -> String {
+		var grid = parseGrid()
+		let yRange = grid.keys.range(\.y)!
+
+		var count = 0
+		while let sand = sandPosition(in: grid, limit: yRange.upperBound + 2) {
+			if sand.y == yRange.upperBound + 2 {
+				break
+			}
+
+			grid[sand] = .sand
+			count += 1
+		}
+
+		return count.description
+	}
+
+	func partTwo() -> String {
+		var grid = parseGrid()
+		let xRange = grid.keys.range(\.x)!
+		let yRange = grid.keys.range(\.y)!
+
+		(xRange.lowerBound - 100000 ..< xRange.upperBound + 100000).forEach {
+			grid[Point(x: $0, y: yRange.upperBound + 2)] = .rock
+		}
+
+		var count = 0
+		while let sand = sandPosition(in: grid, limit: yRange.upperBound + 3) {
+			grid[sand] = .sand
+			count += 1
+
+			if sand.y == 0 {
+				break
+			}
+		}
+
+		return count.description
+	}
+
+	fileprivate func parseGrid() -> [Point: Tile] {
+		input
+			.split(separator: "\n")
+			.reduce(into: [Point: Tile]()) { grid, line in
+				let points = line.integers
+					.chunks(ofCount: 2)
+					.map { Point(x: $0.first!, y: $0.dropFirst().first!) }
+
+				var current = points.first!
+				for point in points.dropFirst() {
+					if point.x == current.x {
+						let range = point.y < current.y
+							? point.y ... current.y
+							: current.y ... point.y
+
+						for y in range {
+							grid[Point(x: current.x, y: y)] = .rock
+						}
+					} else {
+						let range = point.x < current.x
+							? point.x ... current.x
+							: current.x ... point.x
+
+						for x in range {
+							grid[Point(x: x, y: current.y)] = .rock
+						}
+					}
+
+					current = point
+				}
+			}
+	}
+
+	fileprivate func displayGrid(_ grid: [Point: Tile]) {
+		let xRange = grid.keys.range(\.x)!
+		let yRange = grid.keys.range(\.y)!
+
+		for y in yRange {
+			let line = xRange
+				.map { grid[Point(x: $0, y: y)]?.description ?? " " }
+				.joined()
+			print(line)
+		}
+	}
+
+	fileprivate func sandPosition(
+		droppingFrom start: Point = Point(x: 500, y: 0),
+		in grid: [Point: Tile],
+		limit: Int
+	) -> Point? {
+		var origin = start
+
+		while grid[origin] == nil {
+			origin.y += 1
+
+			if origin.y == limit {
+				return origin
+			}
+		}
+
+		origin.y -= 1
+
+		let bottomLeft = Point(x: origin.x - 1, y: origin.y + 1)
+		let bottomRight = Point(x: origin.x + 1, y: origin.y + 1)
+		if grid[bottomLeft] == nil {
+			return sandPosition(droppingFrom: bottomLeft, in: grid, limit: limit)
+		} else if grid[bottomRight] == nil {
+			return sandPosition(droppingFrom: bottomRight, in: grid, limit: limit)
+		}
+
+		return origin
+	}
+}
diff --git a/2022/Sources/2022/main.swift b/2022/Sources/2022/main.swift
@@ -1,6 +1,6 @@
 import Foundation
 
-typealias CurrentDay = Day13
+typealias CurrentDay = Day14
 
 let testInput = """
 <Insert your test input here>