Fixing graphs algorithm and updating readme with timings from Maven build run (on my mac)

Author: jwcarman

README.md

@@ -20,23 +20,23 @@ The project is structured as follows:
 Here are the solutions I have implemented along with the time it took to run each one:
 | Solution | Timing (ms) |
 | :--- | ---: |
-| [Day 1: Historian Hysteria](src/test/kotlin/adventofcode/Day01Test.kt) | 49 |
-| [Day 2: Red-Nosed Reports](src/test/kotlin/adventofcode/Day02Test.kt) | 45 |
-| [Day 3: Mull It Over](src/test/kotlin/adventofcode/Day03Test.kt) | 39 |
-| [Day 4: Ceres Search](src/test/kotlin/adventofcode/Day04Test.kt) | 120 |
-| [Day 5: Print Queue](src/test/kotlin/adventofcode/Day05Test.kt) | 50 |
-| [Day 6: Guard Gallivant](src/test/kotlin/adventofcode/Day06Test.kt) | 778 |
-| [Day 7: Bridge Repair](src/test/kotlin/adventofcode/Day07Test.kt) | 69 |
-| [Day 8: Resonant Collinearity](src/test/kotlin/adventofcode/Day08Test.kt) | 77 |
-| [Day 9: Disk Fragmenter](src/test/kotlin/adventofcode/Day09Test.kt) | 1,012 |
-| [Day 10: Hoof It](src/test/kotlin/adventofcode/Day10Test.kt) | 583 |
-| [Day 11: Plutonian Pebbles](src/test/kotlin/adventofcode/Day11Test.kt) | 119 |
-| [Day 12: Garden Groups](src/test/kotlin/adventofcode/Day12Test.kt) | 221 |
-| [Day 13: Claw Contraption](src/test/kotlin/adventofcode/Day13Test.kt) | 54 |
-| [Day 14: Restroom Redoubt](src/test/kotlin/adventofcode/Day14Test.kt) | 474 |
-| [Day 15: Warehouse Woes](src/test/kotlin/adventofcode/Day15Test.kt) | 129 |
-| [Day 16: Reindeer Maze](src/test/kotlin/adventofcode/Day16Test.kt) | 261 |
-| [Day 17: Chronospatial Computer](src/test/kotlin/adventofcode/Day17Test.kt) | 93 |
-| [Day 18: RAM Run](src/test/kotlin/adventofcode/Day18Test.kt) | 476 |
-| [Day 19: Linen Layout](src/test/kotlin/adventofcode/Day19Test.kt) | 60 |
-| [Day 20: Race Condition](src/test/kotlin/adventofcode/Day20Test.kt) | 474 |
+| [Day 1: Historian Hysteria](src/test/kotlin/adventofcode/Day01Test.kt) | 7 |
+| [Day 2: Red-Nosed Reports](src/test/kotlin/adventofcode/Day02Test.kt) | 8 |
+| [Day 3: Mull It Over](src/test/kotlin/adventofcode/Day03Test.kt) | 7 |
+| [Day 4: Ceres Search](src/test/kotlin/adventofcode/Day04Test.kt) | 67 |
+| [Day 5: Print Queue](src/test/kotlin/adventofcode/Day05Test.kt) | 8 |
+| [Day 6: Guard Gallivant](src/test/kotlin/adventofcode/Day06Test.kt) | 661 |
+| [Day 7: Bridge Repair](src/test/kotlin/adventofcode/Day07Test.kt) | 24 |
+| [Day 8: Resonant Collinearity](src/test/kotlin/adventofcode/Day08Test.kt) | 5 |
+| [Day 9: Disk Fragmenter](src/test/kotlin/adventofcode/Day09Test.kt) | 1,007 |
+| [Day 10: Hoof It](src/test/kotlin/adventofcode/Day10Test.kt) | 474 |
+| [Day 11: Plutonian Pebbles](src/test/kotlin/adventofcode/Day11Test.kt) | 96 |
+| [Day 12: Garden Groups](src/test/kotlin/adventofcode/Day12Test.kt) | 119 |
+| [Day 13: Claw Contraption](src/test/kotlin/adventofcode/Day13Test.kt) | 11 |
+| [Day 14: Restroom Redoubt](src/test/kotlin/adventofcode/Day14Test.kt) | 452 |
+| [Day 15: Warehouse Woes](src/test/kotlin/adventofcode/Day15Test.kt) | 52 |
+| [Day 16: Reindeer Maze](src/test/kotlin/adventofcode/Day16Test.kt) | 134 |
+| [Day 17: Chronospatial Computer](src/test/kotlin/adventofcode/Day17Test.kt) | 55 |
+| [Day 18: RAM Run](src/test/kotlin/adventofcode/Day18Test.kt) | 248 |
+| [Day 19: Linen Layout](src/test/kotlin/adventofcode/Day19Test.kt) | 28 |
+| [Day 20: Race Condition](src/test/kotlin/adventofcode/Day20Test.kt) | 515 |

src/main/kotlin/adventofcode/util/graph/Graphs.kt

@@ -59,19 +59,17 @@ object Graphs {
         return ShortestPaths(start, dist, pred)
     }
 
-    private data class Reachable<V>(val steps: Int, val vertex: V)
-
     fun <V> reachable(start: V, maxSteps: Int = Int.MAX_VALUE, neighbors: (V) -> List<V>): Set<V> {
         val visited = mutableSetOf<V>()
-        val stack = mutableListOf(Pair(start, 0))
-        while (stack.isNotEmpty()) {
-            val (current, steps) = stack.removeFirst()
-            if (steps > maxSteps) continue
-            if (current !in visited) {
-                visited.add(current)
-                neighbors(current)
-                    .filter { it !in visited }
-                    .forEach { stack.add(Pair(it, steps + 1)) }
+        val queue = mutableListOf(Pair(start, 0))
+        while (queue.isNotEmpty()) {
+            val (current, steps) = queue.removeFirst()
+            if (visited.add(current) && steps < maxSteps) {
+                queue.addAll(
+                    neighbors(current)
+                        .filter { n -> n !in visited }
+                        .map { n -> Pair(n, steps + 1) }
+                )
             }
         }
         return visited