day 6

Sources/Day06/Day06.swift

@@ -6,17 +6,46 @@
 
 import AoCTools
 
+private struct Race {
+    let time: Int
+    let distance: Int
+
+    func waysToWin() -> Int {
+        var win = 0
+        for press in 1 ..< time {
+            let distance = press * (time - press)
+            if distance > self.distance {
+                win += 1
+            }
+        }
+        return win
+    }
+}
+
 final class Day06: AOCDay {
-
+    private let races: [Race]
+    private let part2Race: Race
+
     init(input: String) {
-        // let input = input ?? Self.input
+        let lines = input.lines
+
+        let times = lines[0].allInts()
+        let distances = lines[1].allInts()
+
+        races = zip(times, distances).map { Race(time: $0, distance: $1) }
+
+        let totalTime = lines[0].replacingOccurrences(of: " ", with: "").allInts()[0]
+        let totalDistance = lines[1].replacingOccurrences(of: " ", with: "").allInts()[0]
+        part2Race = Race(time: totalTime, distance: totalDistance)
     }
 
     func part1() -> Int {
-        return 0
+        races
+            .map { $0.waysToWin() }
+            .reduce(1, *)
     }
 
     func part2() -> Int {
-        return 0
+        part2Race.waysToWin()
     }
 }

Tests/Day06Tests.swift

@@ -7,25 +7,27 @@ import XCTest
 
 final class Day06Tests: XCTestCase {
     let testInput = """
+Time:      7  15   30
+Distance:  9  40  200
 """
 
     func testDay06_part1() throws {
         let day = Day06(input: testInput) 
-        XCTAssertEqual(day.part1(), 0)
+        XCTAssertEqual(day.part1(), 288)
     }
 
     func testDay06_part1_solution() throws {
         let day = Day06(input: Day06.input) 
-        XCTAssertEqual(day.part1(), 0)
+        XCTAssertEqual(day.part1(), 1710720)
     }
 
     func testDay06_part2() throws {
         let day = Day06(input: testInput)
-        XCTAssertEqual(day.part2(), 0)
+        XCTAssertEqual(day.part2(), 71503)
     }
 
     func testDay06_part2_solution() throws {
         let day = Day06(input: Day06.input) 
-        XCTAssertEqual(day.part2(), 0)
+        XCTAssertEqual(day.part2(), 35349468)
     }
 }