Day 2: Compute power of minimum set of cubes

src/main/kotlin/Main.kt

@@ -3,6 +3,8 @@ import day2.Day2
 import day2.Hand
 
 fun main() {
-    println("Day 1: ${Day1.answerOne()} &&  ${Day1.answerTwo()}")
-    println("Day 2: ${Day2.sumOfCompatibleGames("src/main/resources/day2/input.txt", Hand(12,13,14))}")
+    println("Day 1-1: ${Day1.answerOne()}")
+    println("Day 1-2: ${Day1.answerTwo()}")
+    println("Day 2-1: ${Day2.sumOfCompatibleGames("src/main/resources/day2/input.txt", Hand(12,13,14))}")
+    println("Day 2-2: ${Day2.powerOfMinimumSetOfCubes("src/main/resources/day2/input.txt")}")
 }

src/main/kotlin/day2/Day2.kt

@@ -9,6 +9,10 @@ object Day2 {
         .map(Game::id)
         .sum()
 
+    fun powerOfMinimumSetOfCubes(file: String) = readGames(file)
+        .map(Game::powerOfHands)
+        .sum()
+
     private fun readGames(file: String): List<Game> =
         File(file)
             .readLines()
@@ -17,15 +21,20 @@ object Day2 {
 }
 
 data class Game(val id: Int, val hands: List<Hand>) {
+
+
     fun isCompatibleWith(hand: Hand) =
-        hand.fitsIn(
-            hands.fold(Hand(0, 0, 0)) { currentMax: Hand, next: Hand ->
-                Hand(
-                    maxOf(currentMax.red, next.red),
-                    maxOf(currentMax.green, next.green),
-                    maxOf(currentMax.blue, next.blue)
-                )
-            })
+        hand.fitsIn(maxOfHands())
+
+    fun powerOfHands() = maxOfHands().let { it.red * it.green * it.blue }
+
+    private fun maxOfHands() = hands.fold(Hand(0, 0, 0)) { currentMax: Hand, next: Hand ->
+        Hand(
+            maxOf(currentMax.red, next.red),
+            maxOf(currentMax.green, next.green),
+            maxOf(currentMax.blue, next.blue)
+        )
+    }
 
     companion object {
 

src/test/kotlin/day2/Day2Test.kt

@@ -5,7 +5,12 @@ import org.junit.jupiter.api.Test
 class Day2Test {
 
     @Test
-    fun readGames() {
+    fun sumOfCompatibleGames() {
         assert(Day2.sumOfCompatibleGames("src/test/resources/day2/input.txt", Hand(12, 13, 14)) == 8)
     }
+
+    @Test
+    fun powerOfMinimumSetOfCubes() {
+        assert(Day2.powerOfMinimumSetOfCubes("src/test/resources/day2/input.txt") == 2286)
+    }
 }