01b

Sources/aoc2021/01.swift

@@ -6,17 +6,70 @@
 //
 
 import Foundation
+
 struct Day01 {
     let inputPath: String
+    
+    
     func run() {
         let input = try! String(contentsOfFile: inputPath)
-        let measurements = input
+        let distances = input
-            .split(separator: "\n")
+            .components(separatedBy: .newlines)
-            .compactMap { Int32($0) }
+            .compactMap { Int($0) }
-            .reduce((currentCount: 0, lastValue: Int32.max)) { partialResult, currentValue in
+        runA(distances: distances)
-                let increaseBy = currentValue > partialResult.lastValue ? 1 : 0
+        runB(distances: distances)
-                return (currentCount: partialResult.currentCount + increaseBy, lastValue: currentValue)
+    }
-            }
+    func runA(distances: [Int]) {
+        let measurements = distances.reduce((currentCount: 0, lastValue: Int.max)) { partialResult, currentValue in
+            let increaseBy = currentValue > partialResult.lastValue ? 1 : 0
+            return (currentCount: partialResult.currentCount + increaseBy, lastValue: currentValue)
+        }
         print(measurements.currentCount)
     }
+    
+    func runB(distances: [Int]) {
+        
+        // Sliding window would've been better, but I was too tired to bend reduce to my will. Oh well!
+        var arrA = [Int]()
+        var arrB = [Int]()
+        var arrC = [Int]()
+        var sumA = Int.max
+        var sumB = Int.max
+        var sumC = Int.max
+        var increases = 0
+        
+        for (idx, distance) in distances.enumerated() {
+            arrA.append(distance)
+            if idx == 0 {
+                continue
+            }
+            arrB.append(distance)
+            if idx == 1 {
+                continue
+            }
+            arrC.append(distance)
+            if arrA.count == 3 {
+                sumA = arrA.reduce(0, +)
+                arrA = [Int]()
+                if sumA > sumC {
+                    increases += 1
+                }
+            }
+            if arrB.count == 3 {
+                sumB = arrB.reduce(0, +)
+                arrB = [Int]()
+                if sumB > sumA {
+                    increases += 1
+                }
+            }
+            if arrC.count == 3 {
+                sumC = arrC.reduce(0, +)
+                arrC = [Int]()
+                if sumC > sumB {
+                    increases += 1
+                }
+            }
+        }
+        print(increases)
+    }
 }