Solution 2018-11: Unit test for part 2

Make the range of square sizes configurable to have the
unit test run faster.

Author: rhaendel

src/main/kotlin/de/ronny_h/aoc/year2018/day11/ChronalCharge.kt

@@ -12,7 +12,7 @@ class ChronalCharge : AdventOfCode<String>(2018, 11) {
         PowerCellGrid(input.single().toInt()).find3x3SquareWithLargestTotal()
 
     override fun part2(input: List<String>): String =
-        PowerCellGrid(input.single().toInt()).findSquareWithLargestTotal()
+        PowerCellGrid(input.single().toInt()).findSquareWithLargestTotal(1..300)
 }
 
 class PowerCellGrid(serialNumber: Int) : Grid<Int>(300, 300, -1000) {
@@ -28,8 +28,8 @@ class PowerCellGrid(serialNumber: Int) : Grid<Int>(300, 300, -1000) {
         }.last()
     }
 
-    fun findSquareWithLargestTotal(): String {
-        val max = (1..300)
+    fun findSquareWithLargestTotal(squareSizeRange: IntRange): String {
+        val max = squareSizeRange
             .map {
                 if (it % 10 == 0) println("calc for square size $it")
                 findSquareWithLargestTotalForSize(it)

src/test/kotlin/de/ronny_h/aoc/year2018/day11/ChronalChargeTest.kt

@@ -27,7 +27,6 @@ class ChronalChargeTest : StringSpec({
     }
 
     "part 2: For grid serial number 18, the largest total square is 16x16 with a top-left corner of 90,269" {
-        // takes too long for a unit test (about 22 seconds)
-        // ChronalCharge().part2(listOf("18")) shouldBe "90,269,16"
+        PowerCellGrid(18).findSquareWithLargestTotal(15..17) shouldBe "90,269,16"
     }
 })