Complete challenge 2023-01.

Author: Matthew Judy

Sources/2023/01/Trebuchet.swift

@@ -10,80 +10,128 @@ import Foundation
 import Shared
 
 
-/**
- Day 1 : Trebuchet?!
-
- # Part One
-
- Something is wrong with global snow production, and you've been selected to
- take a look. The Elves have even given you a map; on it, they've used stars
- to mark the top fifty locations that are likely to be having problems.
-
- You've been doing this long enough to know that to restore snow operations,
- you need to check all **fifty stars** by December 25th.
-
- Collect stars by solving puzzles. Two puzzles will be made available on each
- day in the Advent calendar; the second puzzle is unlocked when you complete
- the first. Each puzzle grants **one star**. Good luck!
-
- You try to ask why they can't just use a weather machine ("not powerful
- enough") and where they're even sending you ("the sky") and why your map looks
- mostly blank ("you sure ask a lot of questions") and hang on did you just say
- the sky ("of course, where do you think snow comes from") when you realize
- that the Elves are already loading you into a trebuchet ("please hold still,
- we need to strap you in").
-
- As they're making the final adjustments, they discover that their calibration
- document (your puzzle input) has been **amended** by a very young Elf who was
- apparently just excited to show off her art skills. Consequently, the Elves
- are having trouble reading the values on the document.
-
- The newly-improved calibration document consists of lines of text; each line
- originally contained a specific **calibration value** that the Elves now need
- to recover. On each line, the calibration value can be found by combining
- the **first digit** and the **last digit** (in that order) to form a single
- **two-digit number**.
-
- For example:
-
- ```
- 1abc2
- pqr3stu8vwx
- a1b2c3d4e5f
- treb7uchet
- ```
-
- In this example, the calibration values of these four lines are `12`, `38`,
- `15`, and `77`. Adding these together produces `142`.
-
- Consider your entire calibration document. **What is the sum of all of the
- calibration values?**
- */
+/// Day 1 : Trebuchet?!
+///
+/// # Part One
+///
+/// Something is wrong with global snow production, and you've been selected to
+/// take a look. The Elves have even given you a map; on it, they've used stars
+/// to mark the top fifty locations that are likely to be having problems.
+///
+/// You've been doing this long enough to know that to restore snow operations,
+/// you need to check all **fifty stars** by December 25th.
+///
+/// Collect stars by solving puzzles. Two puzzles will be made available on each
+/// day in the Advent calendar; the second puzzle is unlocked when you complete
+/// the first. Each puzzle grants **one star**. Good luck!
+///
+/// You try to ask why they can't just use a weather machine ("not powerful
+/// enough") and where they're even sending you ("the sky") and why your map
+/// looks mostly blank ("you sure ask a lot of questions") and hang on did you
+/// just say, "the sky" ("of course, where do you think snow comes from") when
+/// you realize that the Elves are already loading you into a trebuchet ("please
+/// hold still, we need to strap you in").
+///
+/// As they're making the final adjustments, they discover that their
+/// calibration document (your puzzle input) has been **amended** by a very
+/// young Elf who was apparently just excited to show off her art skills.
+/// Consequently, the Elves are having trouble reading the values on
+/// the document.
+///
+/// The newly-improved calibration document consists of lines of text; each line
+/// originally contained a specific **calibration value** that the Elves now
+/// need to recover. On each line, the calibration value can be found by
+/// combining the **first digit** and the **last digit** (in that order) to form
+/// a single **two-digit number**.
+///
+/// For example:
+///
+/// ```
+/// 1abc2
+/// pqr3stu8vwx
+/// a1b2c3d4e5f
+/// treb7uchet
+/// ```
+///
+/// In this example, the calibration values of these four lines are `12`, `38`,
+/// `15`, and `77`. Adding these together produces **`142`**.
+///
+/// Consider your entire calibration document. **What is the sum of all of the
+/// calibration values?**
+///
+/// # Part Two
+///
+/// Your calculation isn't quite right. It looks like some of the digits are
+/// actually **spelled out with letters**: `one`, `two`, `three`, `four`,
+/// `five`, `six`, `seven`, `eight`, and `nine` **also** count as
+/// valid "digits".
+///
+/// Equipped with this new information, you now need to find the real first and
+/// last digit on each line. For example:
+///
+/// ```
+/// two1nine
+/// eightwothree
+/// abcone2threexyz
+/// xtwone3four
+/// 4nineeightseven2
+/// zoneight234
+/// 7pqrstsixteen
+/// ```
+///
+/// In this example, the calibration values are `29`, `83`, `13`, `24`, `42`,
+/// `14`, and `76`.  Adding these together produces **`281`**.
+///
+/// **What is the sum of all of the calibration values?**
 @main
 struct Trebuchet: AsyncParsableCommand
 {
-    /// Enumeration for argument which activates "Part Two" behavior
-    enum Mode: String, ExpressibleByArgument, CaseIterable
-    {
-        case modeA
-        case modeB
-    }
-
-    @Option(help: "<#Argument used to activate “Part Two” behavior.#>")
-    var mode: Mode
+    @Flag(help: "Search for both cardinal values ('one', 'two', ...) and integers.")
+    var includeCardinals: Bool = false
 }
 
 
 // MARK: - Command Execution
 
 extension Trebuchet
 {
+    static let cardinalMapping: [(cardinalString: String, arabicString: String, integerString: Int)] = [
+        ("zero",  "0", 0),
+        ("one",   "1", 1),
+        ("two",   "2", 2),
+        ("three", "3", 3),
+        ("four",  "4", 4),
+        ("five",  "5", 5),
+        ("six",   "6", 6),
+        ("seven", "7", 7),
+        ("eight", "8", 8),
+        ("nine",  "9", 9),
+    ]
+
+
     mutating func run() async throws
     {
-        while let inputLine = readLine()
+        let input:          AsyncLineSequence = FileHandle.standardInput.bytes.lines // URL.homeDirectory.appending(path: "Desktop/input.txt").lines
+        let calibrationSum: Int               = try await input.reduce(0)
         {
-            print("\(inputLine)")
+            currentSum, inputLine in
+
+            let integerIndices: [(index: String.Index, intValue: Int)] = Trebuchet.cardinalMapping.reduce(into: [])
+            {
+                result, mapping in
+                result.append(contentsOf: inputLine.indices(of: mapping.arabicString).map { ($0, mapping.integerString) })
+                
+                if (self.includeCardinals)
+                {
+                    result.append(contentsOf: inputLine.indices(of: mapping.cardinalString).map { ($0, mapping.integerString) })
+                }
+            }
+            .sorted { $0.index < $1.index }
+
+            return (currentSum + (integerIndices.first!.intValue * 10) + integerIndices.last!.intValue)
         }
+
+        print(calibrationSum)
     }
 }