Merge pull request #2751 from rrbharath/feat/chebyshev-distance-algorithm

feat(math): add chebyshev distance

Author: keon

algorithms/math/__init__.py

@@ -12,6 +12,7 @@
     modular_inverse,  # type: ignore[no-redef]  # noqa: E402
 )
 from algorithms.math.base_conversion import base_to_int, int_to_base
+from algorithms.math.chebyshev_distance import chebyshev_distance
 from algorithms.math.combination import combination, combination_memo
 from algorithms.math.cosine_similarity import cosine_similarity
 from algorithms.math.decimal_to_binary_ip import (
@@ -66,6 +67,7 @@
 __all__ = [
     "base_to_int",
     "int_to_base",
+    "chebyshev_distance",
     "chinese_remainder_theorem",
     "combination",
     "combination_memo",

algorithms/math/chebyshev_distance.py

@@ -0,0 +1,26 @@
+"""Chebyshev distance — L-infinity distance between two points.
+
+Also known as chessboard distance, it is the maximum absolute difference
+across coordinates. In chess, it is the minimum number of moves a king
+needs to travel between two squares.
+"""
+
+from __future__ import annotations
+
+
+def chebyshev_distance(a: tuple[float, ...], b: tuple[float, ...]) -> float:
+    """Return the Chebyshev (L-infinity) distance between points *a* and *b*.
+
+    Works in any number of dimensions.
+
+    >>> chebyshev_distance((1, 2, 3), (4, 5, 6))
+    3
+    >>> chebyshev_distance((1, 2), (1, 2))
+    0
+    >>> chebyshev_distance((-1, -2), (4, 3))
+    5
+    """
+    if len(a) != len(b):
+        msg = "Points must have the same number of dimensions."
+        raise ValueError(msg)
+    return max(abs(x - y) for x, y in zip(a, b, strict=False))

tests/test_math.py

@@ -4,6 +4,7 @@
 
 from algorithms.math import (
     base_to_int,
+    chebyshev_distance,
     chinese_remainder_theorem,
     combination,
     combination_memo,
@@ -616,6 +617,19 @@ def test_complex_numbers(self):
         self.assertEqual(real, real_result)
         self.assertEqual(imag, imag_result)
 
+class TestChebyshevDistance(unittest.TestCase):
+    """[summary]
+    Test for the file chebyshev_distance.py
+
+    Arguments:
+        unittest {[type]} -- [description]
+    """
+
+    def test_chebyshev_distance(self):
+        self.assertEqual(3, chebyshev_distance([1, 2, 3], [4, 5, 6]))
+        self.assertEqual(0, chebyshev_distance([1, 2], [1, 2]))
+        self.assertEqual(5, chebyshev_distance([-1, -2], [4, 3]))
+
 
 if __name__ == "__main__":
     unittest.main()