Day 15 part 1

AoC2018.Runner/AoC2018.Runner.csproj

@@ -28,6 +28,9 @@
     <None Update="Input\day04.txt">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <None Update="Input\day15.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="Input\day14.txt">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>

AoC2018.Runner/Input/day15.txt

@@ -0,0 +1,32 @@
+################################
+######..#######.################
+######...######..#.#############
+######...#####.....#############
+#####....###G......#############
+#####.#G..#..GG..##########..#.#
+#######G..G.G.....##..###......#
+######....G...........#.....####
+#######.G......G........##..####
+######..#..G.......E...........#
+######..G................E..E..#
+####.............E..........#..#
+#####.........#####........##..#
+########.....#######.......#####
+########..G.#########......#####
+#######.....#########....#######
+#######G....#########..G...##.##
+#.#.....GG..#########E##...#..##
+#.#....G....#########.##...#...#
+#....##......#######..###..##E.#
+####G.........#####...####....##
+####..G...............######..##
+####....#.....##############.###
+#..#..###......#################
+#..#..###......#################
+#.....#####....#################
+###########.E.E.################
+###########.E...################
+###########.E..#################
+#############.##################
+#############.##################
+################################

AoC2018.Runner/Input/day18.txt

@@ -0,0 +1,50 @@
+||.|..#|.|.....|..|........|..#..|#...|.........#.
+...#....|#..|......#.|||...#...|...#....|.......#.
+##.#|.#..|.#|....||.|#.#....#.#.###.|..|...|#.#|..
+..||.#|#|#..#.#|...|....||.|...##.....|.....#...#|
+#|..#...#.##|.|.##||..|...|...#||.|...#.##.###|.|.
+#.#||#...#.|#.....|#.......|#.||..|..|#..#.##...#.
+|.||.|.|........|.|.#.|...##.|.||..#....#..|.|#..#
+....#...|#...#....|#.|.|||#.||#....||.......|.#|..
+|#..#..#.|.|#.||#...|.|...|#.||...#...##....|....|
+..#...|......#.#...|#...#|.|......#.|||#.|#.|#.#.|
+..##.#|#|...||....##|.|||.|##|#.....#|...#...###||
+...||......#...|....#.....#|#......#......#..|.|#.
+..........#|.|#..|..#.##.#...#|...#..#...|...#|.||
+|.#..#|###..||...|#|....|...........|...#|#.#..#|.
+|.#..##.........#||.....|#|.###.#.|.....#.|..|.##.
+....#||..#|...|.#...#.|.#.|..#............#.|.....
+...|#...##.#.#.|.||.......#...|.....###.||...##..|
+..|...|#.|.#..|..#|..||.#.....#||.|..#..|..|.||.#.
+#.##||#.#.....||.|.#.......#.|.##|##|#..#|.....|#.
+...#..#.#..#.|.....|.#...|.....###||||..#..##...#.
+...|...|.|.##|..#.#|#....#.#.|#||||....#...|||.#.#
+..|...##..|#||..||#|#..|..|##.|..##...#...#|.##.#|
+|#...#.#.......|...||...##.|.||#.....#.||.......#|
+..#.....#|.#...#...|.#|.#.#|.....#.##.#|.....#....
+......#|..|||.#.#..||..|.|..|...##.....#..#.###...
+....##..#..|..||..##.||#.|..|.#...#..||#...#..|...
+.||......||#.#|#.##.||.#..|..#..#..#.|..|#|..||...
+|...#|...|....|.|.|.....||.|.|..|#.#.#..|.#..##..#
+..|..#..#.|.##.....|#..|..#|.|..#.#.|..|..#|..|...
+....|...#..|#...#.###.|..####..||#..|.|.|......||.
+.....||.#.|##|.....|##.||.##..#.#.|...#.#...||.#..
+.|#..#.|...||#..|.#..#....###.#...#.....||......##
+||...#||..#...##.|..|...|#.|#|.|##|#|##....#..#|..
+.|..#.##..|......#|.....||..|||||||#.#.|#..|.|.|..
+|#.##.|............##||##.#...#.#........|..#.....
+.||....|.#||#|.#..|..........#....##.#.|...#.||..|
+......|...#.......##.#.#|#......#||##...#..#||.|#.
+..||.#..#.#.......|.|.##.#.|...#...###..|...|..|..
+.#....|..||##.|.|..#.|.#|..#|......#....#.#.|..||.
+.........|....|.#..|...|.|#....#..|.....#...|#|#.|
+.|.||..|#.|...##.|.#...#..|.||||..##.##|#.##.|##.#
+.|#.#.....#||#.#....||.|..##......|.#.|..#...##||.
+|.#........|..|........#..#.#....|.|#.......#.|...
+#..##.|.#......#...#..#.|.....#|.|.|#.##..#|...|..
+..#....####....|..||...||..||.|.|...##.#..|||.||.|
+...|..#.|||.||.||.#|...|..#.##..|#..........#.##|.
+..|..||.#|.|.#..|.###|#.|....|.||.....|.........#.
+#.|#.....#.|.#|#.|.#.#||...|.....||..|..|.##|#.|#|
+..|...||#.|.#...|#.#....#.|##.#.|.....##..#..|.#..
+..|.#...|.|...##|..#.#|.#|..|..#.|#.#...#|#.#||#..

AoC2018.Runner/Properties/launchSettings.json

@@ -2,7 +2,7 @@
   "profiles": {
     "AoC2018.Runner": {
       "commandName": "Project",
-      "commandLineArgs": "14 2"
+      "commandLineArgs": "15 1"
     }
   }
 }

AoC2018.Solutions/Day15/Elf.cs

@@ -0,0 +1,12 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System;
+
+    public class Elf : Unit
+    {
+        public override string ToString()
+        {
+            return "E";
+        }
+    }
+}

AoC2018.Solutions/Day15/Goblin.cs

@@ -0,0 +1,12 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System;
+
+    public class Goblin : Unit
+    {
+        public override string ToString()
+        {
+            return "G";
+        }
+    }
+}

AoC2018.Solutions/Day15/LocationHelper.cs

@@ -0,0 +1,18 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System.Collections.Generic;
+    using System.Linq;
+
+    public static class LocationHelper
+    {
+        public static (int X, int Y) GetCoordinates(int location, int yOffset)
+        {
+            return (location % yOffset, location / yOffset);
+        }
+
+        public static int GetLocation(int x, int y, int yOffset)
+        {
+            return x + (y * yOffset);
+        }
+    }
+}

AoC2018.Solutions/Day15/MapSpace.cs

@@ -0,0 +1,41 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System;
+
+    public class MapSpace
+    {
+        public int Location { get; set; }
+
+        public Unit Unit { get; set; }
+
+        public static MapSpace Parse(char input, int location)
+        {
+            var result = new MapSpace();
+
+            switch (input)
+            {
+                case '#':
+                    return null;
+
+                case '.':
+                    break;
+
+                case 'E':
+                    result.Unit = new Elf { CurrentLocation = result };
+                    break;
+
+                case 'G':
+                    result.Unit = new Goblin { CurrentLocation = result };
+                    break;
+            }
+
+            result.Location = location;
+            return result;
+        }
+
+        public override string ToString()
+        {
+            return this.Unit?.ToString() ?? ".";
+        }
+    }
+}

AoC2018.Solutions/Day15/MapSpaceExtensions.cs

@@ -0,0 +1,10 @@
+namespace AoC2018.Solutions.Day15
+{
+    public static class MapSpaceExtensions
+    {
+        public static bool IsEmpty(this MapSpace space)
+        {
+            return space.Unit == null;
+        }
+    }
+}

AoC2018.Solutions/Day15/Part01.cs

@@ -0,0 +1,40 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System;
+
+    public class Part01 : ISolution
+    {
+        public string Solve(string input)
+        {
+            var currentState = State.Parse(input);
+            int rounds = 0;
+
+            ////Console.WriteLine(currentState.ToString());
+
+            while (true)
+            {
+                bool roundCompleted = currentState.Round();
+
+                if (roundCompleted)
+                {
+                    rounds++;
+                }
+
+                if (currentState.IsCombatEnded())
+                {
+                    break;
+                }
+
+                ////Console.WriteLine();
+                ////Console.WriteLine($"Round {rounds}");
+                ////Console.WriteLine(currentState.ToString());
+            }
+
+            ////Console.WriteLine();
+            ////Console.WriteLine($"Combat ended during round {rounds + 1}");
+            ////Console.WriteLine(currentState.ToString());
+
+            return (rounds * currentState.TotalRemainingHitPoints()).ToString();
+        }
+    }
+}

AoC2018.Solutions/Day15/State.cs

@@ -0,0 +1,32 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+
+    public class State
+    {
+        public int YOffset { get; set; }
+
+        public MapSpace[] Map { get; set; }
+
+        public int MaxY { get; set; }
+
+        public static State Parse(string input)
+        {
+            string[] inputRows = input.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
+            int yOffset = inputRows[0].Length;
+            char[] mapChars = inputRows.SelectMany(x => x.ToCharArray()).ToArray();
+            MapSpace[] map = Enumerable.Range(0, mapChars.Length).Select(x => MapSpace.Parse(mapChars[x], x)).ToArray();
+
+            return new State { Map = map, YOffset = yOffset, MaxY = inputRows.Length };
+        }
+
+        public override string ToString()
+        {
+            string mapString = string.Join(string.Empty, this.Map.Select(x => x?.ToString() ?? "#"));
+            IEnumerable<string> rows = Enumerable.Range(0, this.Map.Length / this.YOffset).Select(x => mapString.Substring(x * this.YOffset, this.YOffset));
+            return string.Join(Environment.NewLine, rows);
+        }
+    }
+}

AoC2018.Solutions/Day15/StateExtensions.cs

@@ -0,0 +1,68 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System.Collections.Generic;
+    using System.Linq;
+
+    public static class StateExtensions
+    {
+        public static bool Round(this State initialState)
+        {
+            // Every unit gets a turn, taken in reading order.
+            // (we get reading order just by iterating the original
+            // state
+            State currentState = initialState;
+
+            // Get the units. Note that it is important to materialise this collection immediately,
+            // otherwise we run the risk of double moving units as we iterate through the map.
+            Unit[] units = initialState.Map.Where(x => x?.Unit != null).OrderBy(x => x.Location).Select(x => x.Unit).ToArray();
+
+            foreach (Unit current in units)
+            {
+                if (currentState.IsCombatEnded())
+                {
+                    return false;
+                }
+
+                // Make sure it hasn't been killed already
+                if (!current.IsKilled())
+                {
+                    current.TakeTurn(currentState);
+                }
+            }
+
+            return true;
+        }
+
+        public static IEnumerable<MapSpace> GetAdjacentSpaces(this State state, MapSpace space)
+        {
+            // Note: because we know the caverns in question are walled all around, we
+            // don't need to worry about bounds checking. If this wasn't the case we'd
+            // need to check to see if the space we're looking at was on the edge of the
+            // map before checking the adjacent spaces.
+            int[] adjacentLocations = new[]
+            {
+                space.Location - state.YOffset,
+                space.Location - 1,
+                space.Location + 1,
+                space.Location + state.YOffset,
+            };
+
+            return adjacentLocations.Select(x => state.Map[x]).Where(x => x != null);
+        }
+
+        public static IEnumerable<MapSpace> GetEmptyAdjacentSpaces(this State state, MapSpace space)
+        {
+            return state.GetAdjacentSpaces(space).Where(MapSpaceExtensions.IsEmpty);
+        }
+
+        public static bool IsCombatEnded(this State state)
+        {
+            return !state.Map.Any(x => x?.Unit is Elf) || !state.Map.Any(x => x?.Unit is Goblin);
+        }
+
+        public static int TotalRemainingHitPoints(this State state)
+        {
+            return state.Map.Sum(x => x?.Unit?.HitPoints ?? 0);
+        }
+    }
+}

AoC2018.Solutions/Day15/Unit.cs

@@ -0,0 +1,13 @@
+namespace AoC2018.Solutions.Day15
+{
+    using System;
+
+    public abstract class Unit
+    {
+        public MapSpace CurrentLocation { get; set; }
+
+        public int AttackStrength { get; set; } = 3;
+
+        public int HitPoints { get; set; } = 200;
+    }
+}