day 2 part 2

day02/source/day02.swift

@@ -4,40 +4,13 @@ import Foundation
 
 @main
 struct Day02 {
-    #if hasFeature(Embedded)
-    static func main() {
-        gfxInitDefault()
-        consoleInit(GFX_TOP, nil)
-
-        run()
-
-        // Main loop
-        while aptMainLoop() {
-            hidScanInput()
-            let kDown = hidKeysDown()
-            if kDown & KEY_START != 0 {
-                break // break in order to return to hbmenu
-            }
-
-            gfxFlushBuffers()
-            gfxSwapBuffers()
-        }
-
-        gfxExit()
-    }
-
-    #else
-    static func main() {
-        run()
-    }
-    #endif
-
     static func run() {
         print("Parsing...")
         let parsed = parseInput(realInput)
         print("Running Part 1...")
         part1(parsed)
-        //part2(parsed)
+        print("Running Part 2...")
+        part2(parsed)
         print("Finished!")
     }
 
@@ -45,10 +18,10 @@ struct Day02 {
 
     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
-            })
+            //.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!)!)
@@ -72,8 +45,61 @@ struct Day02 {
     }
 
     static func part2(_ input: ParsedInput) {
+        var sum: UInt64 = 0
+        for (lhs, rhs) in input {
+            for cur in lhs...rhs {
+                let scur = String(cur)
+                let curCount = scur.count
+                guard curCount > 1 else { continue }
 
+                nextLength: for checkOffset in 0...((curCount / 2) - 1) {
+                    let sub = scur[scur.startIndex...scur.index(scur.startIndex, offsetBy: checkOffset)]
+                    let subCount = sub.count
+
+                    for windowOffset in stride(from: subCount, to: curCount, by: subCount) {
+                        guard windowOffset + subCount <= curCount else { break nextLength }
+                        let winStartIdx = scur.index(scur.startIndex, offsetBy: windowOffset)
+                        let winEndIdx = scur.index(winStartIdx, offsetBy: subCount - 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()
+        consoleInit(GFX_TOP, nil)
+
+        run()
+
+        while aptMainLoop() {
+            hidScanInput()
+            let kDown = hidKeysDown()
+            if kDown & KEY_START != 0 {
+                break
+            }
+
+            gfxFlushBuffers()
+            gfxSwapBuffers()
+        }
+
+        gfxExit()
+    }
+
+    #else
+    static func main() {
+        run()
+    }
+    #endif
+
 }
 
 let testInput = """