day 2 part 2

day02/source/day02.swift

@@ -4,6 +4,74 @@ import Foundation
 
 @main
 struct Day02 {
+    static func run() {
+        print("Parsing...")
+        let parsed = parseInput(realInput)
+        //print("Running Part 1...")
+        //part1(parsed)
+        print("Running Part 2...")
+        part2(parsed)
+        print("Finished!")
+    }
+
+    typealias ParsedInput = [(UInt64, UInt64)]
+
+    static func parseInput(_ input: String) -> ParsedInput {
+        input.split(separator: ",")
+            //.filter({ line in
+            //    let split = line.split(separator: "-")
+            //    return String(split[0]).count % 2 == 0 || String(split[1]).count % 2 == 0
+            //})
+            .map({ line in
+                let split = line.split(separator: "-")
+                return (UInt64(split.first!)!, UInt64(split.last!)!)
+            })
+    }
+
+    static func part1(_ input: ParsedInput) {
+        var sum: UInt64 = 0
+        for (lhs, rhs) in input {
+            for cur in lhs...rhs {
+                let cnt = String(cur).count
+                guard cnt % 2 == 0 else { continue }
+                let low = cur % UInt64(pow(10, (Double(cnt) / 2)))
+                let hi = low * UInt64(pow(10, (Double(cnt) / 2)))
+                if cur == hi + low {
+                    sum += cur
+                }
+            }
+        }
+        print("Part 1: \(sum)")
+    }
+
+    static func part2(_ input: ParsedInput) {
+        var sum: UInt64 = 0
+        for (lhs, rhs) in input {
+            for cur in lhs...rhs {
+                let sCur = String(cur)
+                let cnt = sCur.count
+                guard cnt > 1 else { continue }
+
+                nextLength: for checkOffset in 0...((cnt / 2) - 1) {
+                    let sub = sCur[sCur.startIndex...sCur.index(sCur.startIndex, offsetBy: checkOffset)]
+
+                    for windowOffset in stride(from: sub.count, to: cnt, by: sub.count) {
+                        guard windowOffset + (sub.count) <= cnt else { break nextLength }
+                        let winStartIdx = sCur.index(sCur.startIndex, offsetBy: windowOffset)
+                        let winEndIdx = sCur.index(winStartIdx, offsetBy: sub.count - 1)
+                        let window = sCur[winStartIdx...winEndIdx]
+                        if sub != window {
+                            continue nextLength
+                        }
+                    }
+                    sum += cur
+                    break
+                }
+            }
+        }
+        print("Part 2: \(sum)")
+    }
+
     #if hasFeature(Embedded)
     static func main() {
         gfxInitDefault()
@@ -32,48 +100,6 @@ struct Day02 {
     }
     #endif
 
-    static func run() {
-        print("Parsing...")
-        let parsed = parseInput(realInput)
-        print("Running Part 1...")
-        part1(parsed)
-        //part2(parsed)
-        print("Finished!")
-    }
-
-    typealias ParsedInput = [(UInt64, UInt64)]
-
-    static func parseInput(_ input: String) -> ParsedInput {
-        input.split(separator: ",")
-            .filter({ line in
-                let split = line.split(separator: "-")
-                return String(split[0]).count % 2 == 0 || String(split[1]).count % 2 == 0
-            })
-            .map({ line in
-                let split = line.split(separator: "-")
-                return (UInt64(split.first!)!, UInt64(split.last!)!)
-            })
-    }
-
-    static func part1(_ input: ParsedInput) {
-        var sum: UInt64 = 0
-        for (lhs, rhs) in input {
-            for cur in lhs...rhs {
-                let cnt = String(cur).count
-                guard cnt % 2 == 0 else { continue }
-                let low = cur % UInt64(pow(10, (Double(cnt) / 2)))
-                let hi = low * UInt64(pow(10, (Double(cnt) / 2)))
-                if cur == hi + low {
-                    sum += cur
-                }
-            }
-        }
-        print("Part 1: \(sum)")
-    }
-
-    static func part2(_ input: ParsedInput) {
-
-    }
 }
 
 let testInput = """