Add problem 2013 - Detect Squares

Author: anirudhology

problems/math/detect_squares.py

@@ -0,0 +1,36 @@
+from typing import List
+
+
+class DetectSquares:
+
+    def __init__(self):
+        self.coordinates = []
+        self.frequencies = {}
+
+    def add(self, point: List[int]) -> None:
+        self.coordinates.append(point)
+        key = str(point[0]) + "," + str(point[1])
+        if key in self.frequencies:
+            self.frequencies[key] += 1
+        else:
+            self.frequencies[key] = 1
+
+    def count(self, point: List[int]) -> int:
+        x, y = point[0], point[1]
+        result = 0
+        for coordinate in self.coordinates:
+            px, py = coordinate[0], coordinate[1]
+            if abs(px - x) == abs(py - y) and px != x and py != y:
+                key_1 = str(x) + "," + str(py)
+                key_2 = str(px) + "," + str(y)
+                count = 1
+                if key_1 in self.frequencies:
+                    count *= self.frequencies[key_1]
+                else:
+                    count = 0
+                if key_2 in self.frequencies:
+                    count *= self.frequencies[key_2]
+                else:
+                    count = 0
+                result += count
+        return result

tests/math/detect_squares_test.py

@@ -0,0 +1,50 @@
+import unittest
+
+from problems.math.detect_squares import DetectSquares
+
+
+class TestDetectSquares(unittest.TestCase):
+
+    def test_add_and_count(self):
+        detect_squares = DetectSquares()
+
+        # Adding points
+        detect_squares.add([1, 2])
+        detect_squares.add([2, 1])
+        detect_squares.add([1, 0])
+        detect_squares.add([0, 1])
+
+        # No squares should exist initially
+        self.assertEqual(detect_squares.count([1, 1]), 0)
+
+        # Adding points to form a square
+        detect_squares.add([2, 2])
+        self.assertEqual(detect_squares.count([1, 1]), 1)
+
+        # Adding a point to form a second square
+        detect_squares.add([0, 0])
+        self.assertEqual(detect_squares.count([1, 1]), 2)
+
+    def test_no_squares(self):
+        ds = DetectSquares()
+
+        # No points added, no squares should exist
+        self.assertEqual(ds.count([0, 0]), 0)
+
+    def test_multiple_same_points(self):
+        ds = DetectSquares()
+
+        # Adding the same point multiple times
+        ds.add([0, 0])
+        ds.add([0, 0])
+        ds.add([1, 1])
+        ds.add([1, 1])
+        ds.add([0, 1])
+        ds.add([1, 0])
+
+        # Two squares are formed
+        self.assertEqual(ds.count([0, 0]), 2)
+
+
+if __name__ == '__main__':
+    unittest.main()