38 lines
1.1 KiB
Swift
38 lines
1.1 KiB
Swift
import Foundation
|
|
|
|
enum Color: Character, CustomStringConvertible {
|
|
case r = "r"
|
|
case g = "g"
|
|
case u = "u"
|
|
case w = "w"
|
|
case b = "b"
|
|
var description: String { return String(self.rawValue) }
|
|
}
|
|
|
|
func readInput(_ filePath: String) throws -> ([[Color]], [[Color]]) {
|
|
let content = try String(contentsOfFile: filePath, encoding: .ascii)
|
|
let lines = content.split(separator: "\n")
|
|
let towels = lines[0].split(separator: ", ").map { $0.compactMap(Color.init) }
|
|
let patterns = lines[1..<lines.count].map { $0.compactMap(Color.init) }
|
|
return (towels, patterns)
|
|
}
|
|
|
|
var cache: [[Color]: Int] = [:]
|
|
func matches(_ pattern: [Color], _ towels: [[Color]]) -> Int {
|
|
if pattern.count == 0 {
|
|
return 1
|
|
}
|
|
if let cached = cache[pattern] {
|
|
return cached
|
|
}
|
|
let r = towels
|
|
.filter { pattern.starts(with: $0) }
|
|
.map { matches(Array(pattern[$0.count..<pattern.count]), towels) }
|
|
.reduce(0, +)
|
|
cache[pattern] = r
|
|
return r
|
|
}
|
|
|
|
let (towels, patterns) = try readInput(CommandLine.arguments[1])
|
|
print(patterns.reduce(0) { s, p in s + matches(p, towels) })
|