From b744356b9515b100e6038dc131159feeb255278f Mon Sep 17 00:00:00 2001
From: Lubos Kolouch <lubos@kolouch.net>
Date: Tue, 11 Feb 2025 15:11:02 +0100
Subject: Challenge 308 LK Perl Python

---
 challenge-308/lubos-kolouch/python/ch-1.py | 54 ++++++++++++++++++++++++
 challenge-308/lubos-kolouch/python/ch-2.py | 68 ++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+)
 create mode 100644 challenge-308/lubos-kolouch/python/ch-1.py
 create mode 100644 challenge-308/lubos-kolouch/python/ch-2.py

(limited to 'challenge-308/lubos-kolouch/python')

diff --git a/challenge-308/lubos-kolouch/python/ch-1.py b/challenge-308/lubos-kolouch/python/ch-1.py
new file mode 100644
index 0000000000..227a3fa942
--- /dev/null
+++ b/challenge-308/lubos-kolouch/python/ch-1.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+"""
+Task 1: Count Common
+
+Given two arrays of strings, str1 and str2,
+return the count of common strings in both arrays.
+
+Examples:
+  Input: str1 = ["perl", "weekly", "challenge"]
+         str2 = ["raku", "weekly", "challenge"]
+  Output: 2
+
+  Input: str1 = ["perl", "raku", "python"]
+         str2 = ["python", "java"]
+  Output: 1
+
+  Input: str1 = ["guest", "contribution"]
+         str2 = ["fun", "weekly", "challenge"]
+  Output: 0
+
+"""
+
+import unittest
+
+# typedef: Define a type alias for list of strings.
+StrList = list[str]
+
+
+def count_common(str1: StrList, str2: StrList) -> int:
+    """
+    Count the number of common strings between two lists.
+    """
+    return len(set(str1).intersection(str2))
+
+
+class TestCountCommon(unittest.TestCase):
+
+    def test_example1(self):
+        self.assertEqual(
+            count_common(["perl", "weekly", "challenge"],
+                         ["raku", "weekly", "challenge"]), 2)
+
+    def test_example2(self):
+        self.assertEqual(
+            count_common(["perl", "raku", "python"], ["python", "java"]), 1)
+
+    def test_example3(self):
+        self.assertEqual(
+            count_common(["guest", "contribution"],
+                         ["fun", "weekly", "challenge"]), 0)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/challenge-308/lubos-kolouch/python/ch-2.py b/challenge-308/lubos-kolouch/python/ch-2.py
new file mode 100644
index 0000000000..11b038dc85
--- /dev/null
+++ b/challenge-308/lubos-kolouch/python/ch-2.py
@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+"""
+Module: xor_decode
+Task 2: Decode XOR
+
+Given an encoded array where each element is the XOR of consecutive elements from the original array,
+this module provides a function to restore the original array from the encoded array and an initial value.
+
+The encoding is defined as:
+    encoded[i] = original[i] XOR original[i+1]
+
+Example:
+    Input:  encoded = [1, 2, 3], initial = 1
+    Output: [1, 0, 2, 1]
+"""
+
+from typing import NewType
+import unittest
+
+# Type definitions for clarity
+EncodedArray = NewType("EncodedArray", list[int])  # EncodedArray: list of int
+OriginalArray = list[int]  # OriginalArray: list of int
+
+
+def decode_xor(encoded: list[int], initial: int) -> OriginalArray:
+    """
+    Decode the original array from an encoded array and an initial value.
+
+    The encoded array is defined such that:
+        encoded[i] = original[i] XOR original[i+1]
+
+    Args:
+        encoded (List[int]): A list of integers representing the XOR encoded array.
+        initial (int): The first element of the original array.
+
+    Returns:
+        List[int]: The decoded original array.
+
+    Examples:
+        >>> decode_xor([1, 2, 3], 1)
+        [1, 0, 2, 1]
+    """
+    original = [initial]
+    for value in encoded:
+        # The inverse of XOR: original[i+1] = original[i] XOR encoded[i]
+        original.append(original[-1] ^ value)
+    return original
+
+
+# Unit tests
+class TestDecodeXOR(unittest.TestCase):
+    """Unit tests for the decode_xor function."""
+
+    def test_example1(self):
+        """Test with first example."""
+        self.assertEqual(decode_xor([1, 2, 3], 1), [1, 0, 2, 1])
+
+    def test_example2(self):
+        """Test with second example."""
+        self.assertEqual(decode_xor([6, 2, 7, 3], 4), [4, 2, 0, 7, 4])
+
+    def test_empty_encoded(self):
+        """Test with an empty encoded array."""
+        self.assertEqual(decode_xor([], 10), [10])
+
+
+if __name__ == '__main__':
+    unittest.main()
-- 
cgit