Add Sliding_Window_XOR working solution

bit_manipulation/sliding_window_xor.py

@@ -0,0 +1,102 @@
+"""
+Author  : Abhiraj Mandal
+Date    : October 3, 2025
+
+This is a pure Python implementation to calculate the cumulative XOR of all
+sliding windows of size window_size in an array generated via a linear recurrence.
+
+The problem is :
+Given parameters array_length, window_size, first_element, multiplier, increment,
+modulo, generate an array:
+
+    arr[0] = first_element
+    arr[i] = (multiplier * arr[i-1] + increment) % modulo
+Compute the XOR of each window of size window_size, and cumulatively XOR all windows.
+"""
+
+
+class SlidingWindowXOR:
+    """
+        Use:
+        solver       = SlidingWindowXOR()
+        result = solver.compute(
+        array_length,
+        window_size,
+        first_element,
+        multiplier,
+        increment,
+        modulo
+    )
+
+    """
+
+    def compute(
+        self,
+        array_length: int,
+        window_size: int,
+        first_element: int,
+        multiplier: int,
+        increment: int,
+        modulo: int,
+    ) -> int:
+        """
+        Compute cumulative XOR of all sliding windows of size window_size.
+
+        >>> SlidingWindowXOR().compute(5, 2, 1, 1, 1, 100)
+        4
+        >>> SlidingWindowXOR().compute(2, 1, 2, 3, 4, 5)
+        2
+        """
+        # Generate the array using recurrence
+        arr = [0] * array_length
+        arr[0] = first_element
+        for i in range(1, array_length):
+            arr[i] = (multiplier * arr[i - 1] + increment) % modulo
+
+        x1 = 0  # XOR of current window
+        x2 = 0  # cumulative XOR of all windows
+        left = 0
+
+        for right in range(array_length):
+            x1 ^= arr[right]  # include current element
+            if right - left + 1 > window_size:
+                x1 ^= arr[left]  # remove leftmost element
+                left += 1
+            if right - left + 1 == window_size:
+                x2 ^= x1
+
+        return x2
+
+
+if __name__ == "__main__":
+    solver = SlidingWindowXOR()
+
+    print("************ Testing Sliding Window XOR Algorithm ************\n")
+
+    # Example testcases
+    test_cases = [
+        (100, 20, 3, 7, 1, 997, 1019),
+        (2, 1, 2, 3, 4, 5, 2),
+        (5, 2, 1, 1, 1, 100, 4),
+        (3, 5, 5, 2, 1, 100, 0),
+        (4, 4, 3, 1, 0, 10, 0),
+    ]
+
+    for idx, test_case in enumerate(test_cases, 1):
+        (
+            array_length,
+            window_size,
+            first_element,
+            multiplier,
+            increment,
+            modulo,
+            expected,
+        ) = test_case
+        result = solver.compute(
+            array_length, window_size, first_element, multiplier, increment, modulo
+        )
+        print(f"Testcase {idx}: Expected={expected}, Got={result}")
+        assert result == expected, f"Testcase {idx} failed!"
+
+    print("\nAll test cases successfully passed!")
+    print("********** End of Testing Sliding Window XOR Algorithm **********")