feat(ai): add aggregate height calculation

src/ai/moves/height.py

@@ -0,0 +1,16 @@
+from typing import Any, Optional
+
+import numpy as np
+
+
+def aggregate_height(field: np.ndarray[int, Any]) -> int:
+    """
+    Calculates the aggregate height of the field.
+
+    Args:
+        field: 2D array representing the game field.
+
+    Returns:
+        The aggregate height of the field.
+    """
+    return np.sum(field.shape[0] - np.argmax(field, axis=0))

tests/ai/test_moves.py

@@ -0,0 +1,20 @@
+import unittest
+
+import numpy as np
+from ai.moves.height import aggregate_height
+
+
+class TestFitness(unittest.TestCase):
+    def test_aggregate_height(self):
+        field = np.array(
+            [
+                [0, 0, 0, 0, 1, 1, 0, 0, 0, 0],
+                [0, 1, 1, 1, 1, 1, 1, 0, 0, 1],
+                [0, 1, 1, 0, 1, 1, 1, 1, 1, 1],
+                [1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+                [1, 1, 1, 0, 1, 1, 1, 1, 1, 1],
+                [1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+            ]
+        )
+
+        self.assertEqual(aggregate_height(field), 48)