feat: solved day 15 part 2

2024-12-16 23:51:43 -06:00
parent 3b06f96259
commit 8e64d65e7d
11 changed files with 764 additions and 205 deletions
@@ -0,0 +1,129 @@
+namespace WarehouseWoes;
+
+class WideWarehouseMap : Map
+{
+  private WideWarehouseMap(Dictionary<Position, char> positions) : base(positions) {}
+  
+  public static WideWarehouseMap From(Dictionary<Position, char> positions) => new(positions);
+  public static WideWarehouseMap From(string[] input) => new(ConvertToDictionary(input));
+  
+  public override Map MoveRobot(List<Direction> directions)
+  {
+    var positions = Positions.ToDictionary();
+    var robotPosition = RobotPosition;
+
+    foreach (var direction in directions)
+    {
+      var nextPosition = robotPosition.GetNextPosition(direction);
+      var hasNextPosition = positions.TryGetValue(nextPosition, out var nextPositionValue);
+
+      if (hasNextPosition is false)
+      {
+        continue;
+      }
+      
+      switch (nextPositionValue)
+      {
+        case Wall:
+          continue;
+        case Empty:
+          positions[robotPosition] = Empty;
+          positions[nextPosition] = Robot;
+          robotPosition = nextPosition;
+          continue;
+        case LeftBoxSide:
+        case RightBoxSide:
+          var newPositions = PushBox(nextPosition, direction, positions);
+
+          if (newPositions == positions)
+          {
+            break;
+          }
+
+          positions = newPositions;
+          positions[robotPosition] = Empty;
+          positions[nextPosition] = Robot;
+          robotPosition = nextPosition;
+          break;
+      }
+    }
+    
+    return new WideWarehouseMap(positions);
+  }
+
+  public override int CalculateTotalBoxGpsCoordinates()
+  {
+    var boxes = Positions.Where(kvp => kvp.Value is LeftBoxSide).ToList();
+    return boxes.Select(kvp => kvp.Key).Sum(p => p.GpsCoordinate);
+  }
+  
+  private static Dictionary<Position, Char> PushBox(Position boxPosition, Direction direction, Dictionary<Position, char> currentPositions)
+  {
+    var positions = currentPositions.ToDictionary();
+    var boxPositions = new Queue<Position>();
+    var visitedPositions = new HashSet<Position>();
+    boxPositions.Enqueue(boxPosition);
+    
+    while (boxPositions.Count is not 0)
+    {
+      var currentPosition = boxPositions.Dequeue();
+
+      if (visitedPositions.Contains(currentPosition))
+      {
+        continue;
+      }
+
+      visitedPositions.Add(currentPosition);
+      
+      var nextPosition = currentPosition.GetNextPosition(direction);
+      var hasCurrentPosition = positions.TryGetValue(currentPosition, out var currentPositionValue);
+      var hasNextPosition = positions.TryGetValue(nextPosition, out var nextPositionValue);
+      
+      if (hasCurrentPosition is false || hasNextPosition is false)
+      {
+        return currentPositions;
+      }
+
+      if (nextPositionValue is Wall)
+      {
+        return currentPositions;
+      }
+      
+      switch (currentPositionValue)
+      {
+        case RightBoxSide:
+          {
+            var leftBoxSidePosition = currentPosition.GetNextPosition(Direction.Left);
+            boxPositions.Enqueue(leftBoxSidePosition);
+            break;
+          }
+        case LeftBoxSide:
+          {
+            var rightBoxSidePosition = currentPosition.GetNextPosition(Direction.Right);
+            boxPositions.Enqueue(rightBoxSidePosition);
+            break;
+          }
+      }
+      
+      if (nextPositionValue is Empty)
+      {
+        continue;
+      }
+
+      boxPositions.Enqueue(nextPosition);
+    }
+
+    foreach (var position in visitedPositions.Reverse())
+    {
+      var nextPosition = position.GetNextPosition(direction);
+      
+      var currentValue = positions[position];
+      var nextValue = positions[nextPosition];
+
+      positions[nextPosition] = currentValue;
+      positions[position] = nextValue;
+    }
+    
+    return positions;
+  }
+}