feat: solved day 12 part 2 🥳

2024-12-13 22:01:35 -06:00
parent 9af08b3193
commit a68edab14c
7 changed files with 268 additions and 178 deletions
@@ -0,0 +1,99 @@
+namespace GardenGroups;
+
+class Region
+{
+  public char PlantType { get; }
+  public HashSet<Position> Positions { get; } = [];
+  public int Area => Positions.Count;
+  public int Perimeter { get; private set; }
+
+  private Region(char plantType)
+  {
+    PlantType = plantType;
+  }
+
+  public static Region From(char plantType) => new(plantType);
+  public static Region From(Position position) => new(position.PlantType);
+  
+  public void AddPosition(Position position) => Positions.Add(position);
+  public void IncreasePerimeter() => Perimeter++;
+  public int CalculateFencePriceBasedOnPerimeter() => Area * Perimeter;
+  public int CalculateFencePriceBasedOnSides()
+  {
+    // corners is always
+    // equal to the number
+    // of sides
+    var corners = FindCorners();
+    return corners * Area;
+  }
+
+  private int FindCorners()
+  {
+    var numberOfCorners = 0;
+
+    foreach (var position in Positions)
+    {
+      var hasNeighborAbove = HasNeighborInDirection(Direction.Up, position);
+      var hasNeighborRight = HasNeighborInDirection(Direction.Right, position);
+      var hasNeighborBelow = HasNeighborInDirection(Direction.Down, position);
+      var hasNeighborLeft = HasNeighborInDirection(Direction.Left, position);
+      
+      //  X
+      // XRX
+      //  X
+      if (hasNeighborRight is false && hasNeighborAbove is false)
+      {
+        numberOfCorners++;
+      }
+
+      if (hasNeighborRight is false && hasNeighborBelow is false)
+      {
+        numberOfCorners++;
+      }
+      
+      if (hasNeighborLeft is false && hasNeighborAbove is false)
+      {
+        numberOfCorners++;
+      }
+
+      if (hasNeighborLeft is false && hasNeighborBelow is false)
+      {
+        numberOfCorners++;
+      }
+      
+      // XRX
+      // RRR
+      // XRX
+      var nextPositionRight = position.GetNextPosition(Direction.Right);
+      var nextPositionLeft = position.GetNextPosition(Direction.Left);
+
+      if (hasNeighborRight && hasNeighborAbove && HasNeighborInDirection(Direction.Up, nextPositionRight) is false)
+      {
+        numberOfCorners++;
+      }
+      
+      if (hasNeighborRight && hasNeighborBelow && HasNeighborInDirection(Direction.Down, nextPositionRight) is false)
+      {
+        numberOfCorners++;
+      }
+      
+      if (hasNeighborLeft && hasNeighborAbove && HasNeighborInDirection(Direction.Up, nextPositionLeft) is false)
+      {
+        numberOfCorners++;
+      }
+      
+      if (hasNeighborLeft && hasNeighborBelow && HasNeighborInDirection(Direction.Down, nextPositionLeft) is false)
+      {
+        numberOfCorners++;
+      }
+    }
+    
+    return numberOfCorners;
+  }
+
+  private bool HasNeighborInDirection(Direction direction, Position position)
+  {
+    var nextPosition = position.GetNextPosition(direction);
+    return Positions.Any(p => p.X == nextPosition.X && p.Y == nextPosition.Y);
+  }
+}